Join us for a fascinating conversation with Dr. Subhoja Chakraborty from the University of Central Florida, whose cutting-edge research targets the global challenge of malaria drug resistance. Dr. Chakraborty shares her journey from structure-based drug design during her PhD to her recent collaborative work repurposing human kinase inhibitors as rapid, selective antimalarials against drug-resistant Plasmodium falciparum strains.<h4>In this episode, you'll learn:</h4><ul><li>How structure-guided approaches reveal potential drug targets, including cysteine proteases like falcipain-2, and kinases implicated in malaria's complex life cycle.</li><li>The power of repurposing kinase inhibitors originally developed for cancer and other diseases, focusing on compound 12, which blocks hemozoin formation and protein kinase 6—key steps in parasite survival.</li><li>Lab techniques such as affinity, gel filtration, and size exclusion chromatography for recombinant protein purification—and how troubleshooting is crucial for high-yield, stable complexes.</li><li>Advances in mass spectrometry for characterizing protein interactions, validating drug targets, and mapping molecular pathways pivotal to malaria therapeutics.</li><li>Tips and lessons for new researchers facing the challenges of sample preparation, complex protocols, and working as part of a collaborative team.</li></ul>Dr. Chakraborty’s insights bridge the gap between basic science and translational drug discovery, offering hope for more effective, targeted malaria treatments in a world where resistance to frontline therapies threatens millions.<h4>Referenced Papers:</h4><ul><li>"Plasmodium falciparum protein kinase 6 and hemozoin formation are inhibited by a type II human kinase inhibitor exhibiting antimalarial activity" (Cell Chemical Biology, 2025)</li><li>"New insights of falcipain 2 structure from Plasmodium falciparum 3D7 strain" (BBRC, 2022)</li><li>"Structure-Based Optimization of Protease−Inhibitor Interactions to Enhance Specificity of Human Stefin‑A against Falcipain‑2 from the Plasmodium falciparum 3D7 Strain" (Biochemistry, 2023)</li></ul>If you’re a student, scientist, or simply passionate about advances in infectious disease research, this episode offers actionable insights, inspiring advice, and a front-row seat to innovation in combating malaria.<h3>Video Transcription</h3><h4>From Structural Biology to Drug Discovery: Chromatography and Mass Spectrometry in Malaria Research</h4><h5>Introduction</h5>In this discussion, Subhoja shares insights into her research journey, focusing on malaria drug discovery and the role of modern analytical techniques in biological and biomedical research. The conversation is aimed primarily at undergraduate students and early-career researchers interested in chemistry, biotechnology, and life sciences.<h5>Research Focus: Malaria Drug Discovery and Kinase Targets</h5>Subhoja is currently involved in malaria drug discovery research at the University of Central Florida, where she has been working since beginning her postdoctoral position two years ago. Her earlier PhD research focused on structure-based drug design in malaria, using a combination of in silico approaches, recombinant protein expression, and X-ray crystallography to determine precise three-dimensional structures of target proteins and their inhibitors.This structural perspective provided a foundation for her current work, which centers on drug discovery through compound screening and repurposing. A recent publication from her laboratory explores the use of repurposed mammalian CDK-like kinase inhibitors as potential antimalarial agents. While such kinase inhibitors are well known in cancer and cardiovascular research, their application to malaria targets represents a novel and promising approach.Kinases are attractive drug targets because of their central role in cell signaling and growth pathways. By targeting specific kinases involved in different stages of the malaria parasite life cycle—whether asexual growth, gametocytogenesis, or differentiation—it may be possible to significantly inhibit parasite growth and progression.<h5>Chromatography in Protein Expression and Purification Workflows</h5>Chromatography plays a critical role throughout Subhoja’s research. Her experience spans from basic chromatography techniques during her early training to advanced protein purification workflows using affinity chromatography, gel filtration (size exclusion chromatography), and ion exchange chromatography.Recombinant proteins are routinely purified using affinity resins such as nickel or cobalt, followed by further purification to remove contaminants. Fast Protein Liquid Chromatography (FPLC) enables compact, stepwise purification workflows suitable for producing proteins for in vitro assays.A recurring challenge in this process is the expression of high-molecular-weight proteins, which often accumulate in insoluble fractions or inclusion bodies. Careful selection of expression vectors, host systems, and induction conditions is therefore essential to maximize yield and solubility.<h5>Integrating Size Exclusion Chromatography into the Workflow</h5>Size exclusion chromatography (SEC) is typically used after affinity purification to further improve protein purity. Following elution with imidazole or glutathione, desalting is required to prevent buffer components from interfering with downstream assays. This is often achieved using desalting columns such as G-25 or PD-10.To remove lower-molecular-weight contaminants, finer SEC media—such as Superdex or Sephacryl columns—are employed. Concentration steps using molecular-weight cut-off filters are then applied to obtain the desired protein concentration for functional studies.These iterative purification and troubleshooting steps are a routine part of protein biochemistry and reflect the importance of methodical optimization and careful validation.<h5>The Role of Mass Spectrometry in Biomolecular Characterization</h5>Mass spectrometry is a key analytical tool in Subhoja’s research pipeline, particularly for target identification and validation. In both malaria and cancer research, MS is used alongside chromatography, immunoprecipitation, and pull-down assays to study protein interactions and molecular recognition events.Affinity-based mass spectrometry enables the identification of binding partners and interactors, whether studying proteins, long non-coding RNAs, or protein complexes. Techniques such as native MS, tandem affinity purification, and proximity labeling (e.g., TurboID-based workflows) provide deeper insights into molecular networks and signaling pathways.These approaches are essential for understanding how candidate drug targets function within complex biological systems.<h5>Sample Preparation Challenges in Biological Research</h5>Sample preparation remains one of the most challenging aspects of biological experimentation. Whole-cell lysates contain proteases, nucleases, and other components that can rapidly degrade target molecules. Preventing degradation requires minimizing preparation time, maintaining low temperatures, and using appropriate inhibitor cocktails.Reproducibility is also critical: biological experiments require multiple replicates, and variability is often unavoidable. Careful handling, protocol optimization, and continuous troubleshooting are essential to ensure reliable results, whether preparing samples for chromatography, mass spectrometry, sequencing, or immunoprecipitation.<h5>Advances in Chromatography and MS for Malaria Research</h5>Modern advances in chromatography and mass spectrometry significantly enhance malaria research by enabling precise target identification, quantification, and functional characterization. Drug discovery workflows begin with construct design and recombinant expression, followed by purification and interaction studies.In malaria research, stage-specific parasite biology requires careful extraction and analysis of proteins from different life cycle stages. Tandem affinity MS, immunoprecipitation, and in vivo validation studies help confirm target relevance and therapeutic potential.Recent work on repurposed kinase inhibitors has shown promising results, including inhibition of hemozoin formation—a key detoxification pathway for the malaria parasite—highlighting the potential of such compounds for further development.<h5>Malaria, Drug Resistance, and Global Impact</h5>Malaria remains a major global health burden, with over 600,000 deaths annually and widespread drug resistance complicating treatment. Artemisinin resistance, particularly associated with mutations in the K13 propeller domain, has driven the search for new targets and therapies.During her PhD, Subhoja focused on falcipain-2, a cysteine protease involved in hemoglobin degradation within the parasite. This pathway is critical for parasite survival and has emerged as a promising drug target. Her work revealed that falcipain-2 operates within a larger protein complex responsible for hemoglobin processing and amino acid release.Understanding these molecular mechanisms is essential for developing robust, stage-specific antimalarial strategies.<h5>Advice for Early-Career Researchers</h5>For researchers just starting out, Subhoja emphasizes the importance of hands-on experience. Working directly with cells, lysates, and analytical tools is essential for truly understanding experimental systems. Failure is an inherent part of research, and perseverance is key.Motivation, teamwork, careful sample handling, and thorough preparation all contribute to long-term success. Reading extensively, critically evaluating one’s own work, and appreciating incremental progress are vital aspects of a sustainable research career.Every successful experiment—no matter how small—represents meaningful progress and contributes to the broader goals of science and medicine.<h5>Closing Remarks</h5>The discussion highlights how interdisciplinary approaches combining chromatography, mass spectrometry, structural biology, and biochemistry are driving advances in malaria drug discovery. Through careful experimental design, analytical rigor, and collaborative teamwork, researchers can address complex biological challenges and contribute to global health solutions.<blockquote>This text has been automatically transcribed from a video presentation using AI technology. It may contain inaccuracies and is not guaranteed to be 100% correct.</blockquote><blockquote><h4>Concentrating on Chromatography Podcast</h4>Dive into the frontiers of chromatography, mass spectrometry, and sample preparation with host David Oliva. Each episode features candid conversations with leading researchers, industry innovators, and passionate scientists who are shaping the future of analytical chemistry. From decoding PFAS detection challenges to exploring the latest in AI-assisted liquid chromatography, this show uncovers practical workflows, sustainability breakthroughs, and the real-world impact of separation science. Whether you’re a chromatographer, lab professional, or researcher you'll discover inspiring content!You can find Concentrating on Chromatography Podcast in podcast apps:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://open.spotify.com/show/1wZg67rCjoGju4yhqxI3tL">Spotify</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://podcasts.apple.com/tz/podcast/concentrating-on-chromatography/id1788429185">Apple podcast</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://podscan.fm/podcasts/concentrating-on-chromatography">podscan</a></li></ul>and on <a target="_blank" rel="noopener noreferrer" href="https://www.youtube.com/@ChromatographyTalk/videos">YouTube channel</a></blockquote>

Affinity, Gel Filtration, Size Exclusion Chromatography: Repurposing Kinase Inhibitors for Malaria

In the week of February 9, the following webinars await you in the field of liquid phase and especially HPLC and LC/MS.<blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinars">👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</a></h4>👉 Search and filter in the largest global database with over 5 000 GC, LC, MS and spectroscopy webinars.</blockquote><h5>1. SelectScience: High-Throughput Stability Screening Strategies for Antibody Formulation</h5><ul><li>Tu, 10.2.2026 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5807">Registration</a></li></ul>Learn how high-throughput DLS/SLS and rapid-screening DSC accelerate stability assessment of high-concentration antibody formulations, enabling faster, data-driven biologics development.<h5>2. Phenomenex: Big Scale, Big Wins – Prep Chromatography Explained</h5><ul><li>We, 11.2.2026 10:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5793">Registration</a></li></ul>Learn how to scale analytical methods to preparative HPLC, optimize loading capacity, and understand the limits of preparative columns for pharmaceutical applications.<h5>3. ALS Czech Republic: PFAS in Food &amp; Food Contact Material</h5><ul><li>We, 11.2.2026 15:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5816">Registration</a></li></ul>Get a practical overview of PFAS in food and food contact materials, including EU and US regulations, key analytical challenges, and reliable PFAS testing strategies.<h5>4. New Food Magazine: The Science of Next-Gen Ingredients – Fermentation, Formulation and Function</h5><ul><li>We, 11.2.2026 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5720">Registration</a></li></ul>Explore how fermentation-driven innovation is transforming functional food ingredients and how advanced analytics optimize flavour, functionality, and stability.<h5>5. SCIEX: Accurate Mass Fundamentals – Interpreting and Applying Your Data</h5><ul><li>We, 11.2.2026 19:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5772">Registration</a></li></ul>Session 3 focuses on interpreting and applying accurate mass data to confirm compound identity, move beyond basic quantitation, and troubleshoot results for confident reporting.<h5>6. Agilent Technologies: Process Analytical Techniques – Online HPLC for Real-Time Monitoring and Control of Bioprocesses</h5><ul><li>Th, 12.2.2026 06:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5834">Registration</a></li></ul>Discover how PAT HPLC enables near-real-time monitoring of critical quality attributes in bioprocessing, with a case study on charge-variant control by cation-exchange chromatography.<h5>7. Thermo Fisher Scientific: Introducing the Orbitrap Excedion Pro Hybrid MS</h5><ul><li>Th, 12.2.2026 11:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5889">Registration</a></li></ul>Discover the new Orbitrap Exploris Pro with expanded ETD/EThcD capabilities for confident biopharmaceutical characterization, including intact proteins, PTMs, ADCs, and large biomolecules.<h5>8. Waters Corporation: Planning Your NuGenesis Upgrade – Insights and Best Practices for a Smooth Transition</h5><ul><li>Th, 12.2.2026 19:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5833">Registration</a></li></ul>Learn how to plan a successful NuGenesis upgrade, transition to Windows 11, and unlock new capabilities such as dashboards for real-time operational insights.<h5>9. Thermo Fisher Scientific: Comprehensive Analytical Strategies for Peptide Therapeutics and GLP-1 Agonists with Agilent</h5><ul><li>Th, 12.2.2026 19:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5814">Registration</a></li></ul>Explore analytical workflows for peptide therapeutics, including method development, peptide mapping, GLP-1 QC, and LC-MS strategies across Agilent platforms.<h5>10. Agilent Technologies: Moving from R&amp;D and Limited QC on a UV-Vis-NIR Instrument to Large-Scale QC Using an Autosampler</h5><ul><li>Th, 12.2.2026 20:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/2104">Registration</a></li></ul>This webinar covers practical aspects of adding and using an autosampler to maximize UV-Vis-NIR QC workflows at scale.<h5>11. Agilent Technologies: LC Method Transfer – Hidden Challenges &amp; Absolute Solution</h5><ul><li>Fr, 13.2.2026 06:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5787">Registration</a></li></ul>Discover why LC method transfer between legacy and modern systems is challenging, which hidden parameters affect retention and peak shape, and how to achieve robust, reliable results.

Webinars LabRulezLCMS Week 07/2026

Charge detection mass spectrometry (CDMS) allows direct mass determination of individual ions and is increasingly used to study heterogeneous biological samples. This work demonstrates the use of Orbitrap-based CDMS/Direct Mass Technology (DMT) for quantitative analysis of transthyretin (TTR) tetramer samples below 100 kDa, extending CDMS beyond its traditional qualitative role.DMT resolved wild-type and C-terminally modified TTR homotetramers, as well as hybrid tetramers, enabling kinetic analysis of subunit exchange and stability. The approach also quantified thyroxine binding to TTR variants, revealing differences in binding affinity linked to C-terminal modification. By separating overlapping m/z signals through charge measurement, CDMS enables accurate mass and abundance determination, highlighting its potential for quantitative analysis of complex protein systems.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771">Dissecting Heterogeneous Populations of Protein-Complex Samples Using Direct Mass Technology</a></h4>Robert L. Rider, Jared Hampton, Zhenyu Xi, Carter Lantz, Sangho D. Yun, Weijing Liu, Rosa Viner, Arthur Laganowsky, and David H. Russell*Anal. Chem. 2025, 97, 49, 27057–27063<a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acs.analchem.5c05771">https://doi.org/10.1021/acs.analchem.5c05771</a><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.Transthyretin (TTR) is a homotetrameric transport protein that circulates in plasma and cerebrospinal fluid, delivering thyroxine (T4) and retinol-binding protein–vitamin A complexes. <a href="javascript:void(0);">(1)</a> The stability of the TTR tetramer is central to its physiological role because dissociation into monomers can initiate misfolding and amyloid formation, leading to systemic or hereditary transthyretin amyloidosis. <a href="javascript:void(0);">(2)</a> Subunit exchange between wild-type (WT) and variant TTR proteoforms, including disease-associated mutations such as V30M and V122I, have been implicated in amyloid progression by generating hybrid tetramers (tetramers containing WT and mutant subunits) with altered stabilities. <a href="javascript:void(0);">(3,4)</a> Ligand binding, particularly at the two thyroxine-binding sites located at the dimer–dimer interface, can kinetically stabilize the tetramer and modulate amyloidogenicity. <a href="javascript:void(0);">(5,6)</a> Accurate measurement of both subunit exchange kinetics and ligand binding stoichiometry is therefore critical for elucidating the TTR dynamics and stability.Affinity or sequence tags are widely employed in protein expression, purification, or detection. <a href="javascript:void(0);">(7,8)</a> While these tags are often assumed to be inert, their influence on protein structure and dynamics are rarely examined in detail. <a href="javascript:void(0);">(9,10)</a> Protein tags at the N- and C-terminus of TTR have been shown to have differing gas phase stabilities from those of WT-TTR. <a href="javascript:void(0);">(11)</a> The C-terminus is of particular interest because this region participates in the dimer–dimer interface that governs tetramer stability. <a href="javascript:void(0);">(11,12)</a> Characterizing how the C-terminal tag (CT) (-ASGENLFYQ) affects TTR’s solution stability and ligand binding is not only relevant for understanding TTR dynamics but also provides an example of how expression tags can alter protein dynamics. <a href="javascript:void(0);">(13)</a>Native mass spectrometry (nMS) has been invaluable for characterizing protein complexes, <a href="javascript:void(0);">(14)</a> yet conventional nMS often struggles with heterogeneous samples where overlapping charge state distributions and adduct heterogeneity limit resolution and quantitation. <a href="javascript:void(0);">(15)</a> Charge detection mass spectrometry (CDMS) addresses these limitations by independently measuring the charge and m/z of individual ions, enabling the direct determination of molecular mass and abundance. Development of CDMS has largely focused on achieving higher mass resolution <a href="javascript:void(0);">(16)</a> and extending measurements toward assemblies into the GDa range. <a href="javascript:void(0);">(17,18)</a> However, there is untapped utility for CDMS experiments other than mass and proteoform determination. Jordan et al. showed the capability to assess conformational heterogeneity of mAb aggregates using the added charge dimension that CDMS provides. <a href="javascript:void(0);">(19)</a> The current work demonstrates that CDMS can separate proteoforms with overlapping m/z values based on charge and quantify their relative abundances in complex mixtures. While nMS is already a highly quantitative technique, our results establish CDMS as an equally powerful tool for quantitative analysis in heterogeneous systems. <a href="javascript:void(0);">(20,21)</a>Here, we apply Orbitrap-based CDMS/Direct Mass Technology (DMT) using the selective temporal overview of resonant ions (STORI) approach <a href="javascript:void(0);">(22,23)</a> to quantitatively compare WT-TTR and CT-TTR, focusing on two biologically relevant properties: tetramer stability assessed via subunit exchange kinetics and ligand-binding affinity. Conventional nMS cannot fully resolve the overlapping charge states of WT- and CT-TTR or their ligand-bound states. However, DMT can resolve these species by directly measuring the mass (m/z × charge), enabling quantitation of all proteoforms. The data reveal that the CT tag alters tetramer stability and thyroxine-binding affinity, demonstrating the structural sensitivity of TTR to modifications at its C-terminus. More broadly, this work demonstrates the impact that protein tags can have on native protein interactions and highlights the broader utility of quantitative CDMS for probing heterogeneous biological samples.<h4>Experimental Section</h4><h5>Data Collection</h5>All experiments were conducted on a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/560">Thermo Scientific Q-Exactive UHMR</a> with added DMT capabilities (Bremen, Germany). Before DMT, mass spectra were collected at various resolving powers (6–200k) for each sample, with the instrument parameters reported in the Supporting Information (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Table S1</a>). For DMT experiments, the trapping gas pressure in the HCD cell was reduced to 0.3–0.8 to attenuate the signal intensity to a single ion level, as well as decreasing the UHV pressure to assist ion retention through the entire transient of Orbitrap analysis. We observed no significant difference between mass spectra collected at various HCD cell pressures (Supporting Information, <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Figure S1</a>). For DMT collection, automated ion control (AIC) and 100% target density were used with 200k resolving power.<h4>Results and Discussion</h4>CDMS has emerged as a powerful tool for analyzing heterogeneous biomolecular samples, enabling accurate, direct mass determination by simultaneously measuring the charge and m/z for individual ions. While CDMS has been widely applied for qualitative analyses, its potential for quantitative and less than MDa applications remains underexplored. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>A shows the theoretical mass spectrum of WT-TTR (14+ to 16+) and CT-TTR (15+ to 17+) homotetramers, where the two proteoforms become increasingly resolved as the charge states increase (&lt;3900 m/z). <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>B zooms in on the 14+ (WT) and 15+ (CT) charge states, highlighting their strong overlap, which prevents accurate deconvolution of the proteoforms by conventional methods. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>C displays theoretical distributions for 0, 1, and 2 T4 bound states of both WT- and CT-TTR tetramers, where &lt;3900 m/z has observable separation between all proteoforms. However, for the 14+ and 15+ charge states of WT- and CT-TTR, respectively, the 0 T4- and 1 T4-bound populations overlap (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>D). Furthermore, commonly adducted species (Na+, K+, and Zn2+) observed in experimental spectra broaden these distributions, making it increasingly difficult to distinguish and deconvolute the proteoforms (see <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Figure S2</a>). Here, we employ Orbitrap-based CDMS/DMT to overcome this m/z overlap to resolve and quantify hybrid tetramer formation and T4 binding.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Anal_Chem_2025_97_49_27057_27063_Figure_1_A_Theoretical_mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_47232849d9.jpg" alt="Anal. Chem. 2025, 97, 49, 27057–27063: Figure 1. (A) Theoretical mass spectra of WT-TTR and CT-TTR homotetramers. (B) Zoomed-in view of the 14+ WT-TTR and 15+ CT-TTR distributions to show the large overlap of the proteoforms. (C) Theoretical mass spectra of WT-TTR and CT-TTR homotetramers with thyroxine (T4) binding. (D) Zoomed-in view of the 14+ WT-TTR and 15+ CT-TTR distributions where the 0 and 1 T4 have overlapping distributions. These theoretical distributions do not contain any commonly adducted species (Na+, K+, Zn2+), which broaden the distributions and create more overlap even for the proteoforms in the range 3300–3900 m/z (see Figure S2)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Anal_Chem_2025_97_49_27057_27063_Figure_1_A_Theoretical_mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_47232849d9.jpg 187w," sizes="100vw" width="1417" height="1182"><h5>Thyroxine Binding to TTR Homotetramers</h5>Thyroxine is the less active form of a thyroid hormone important for metabolism that binds to TTR for transport throughout plasma and cerebral spinal fluid. <a href="javascript:void(0);">(31)</a> Turnover of T4 into T3 (active) occurs after dissociation, where it can then modulate gene expression via binding to nuclear receptors. <a href="javascript:void(0);">(32)</a> The TTR tetramer gains substantial stability as it binds up to 2 T4 at the tetramer interface, decreasing tetramer dissociation and SUE. <a href="javascript:void(0);">(33)</a> This has been shown previously to decrease the amyloidogenic rate of TTR, which led to tafamidis (similar in structure to T4) to be designed and is currently the only drug that is approved for clinical treatment of TTR amyloidosis. <a href="javascript:void(0);">(34)</a> Measuring the difference in binding affinity between TTR proteoforms may provide insight into regions of TTR or TTR intermolecular/intramolecular interactions that are important for binding of small molecules such as tafamidis and T4.DMT was further applied to quantify T4 binding to WT- and CT-TTR homotetramers, highlighting the technique’s utility in probing protein–ligand interactions. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig3">Figure 3</a>A shows a representative mass spectrum of TTR homotetramers in the presence of T4. While ligand-bound species can be observed, homotetramers cannot be confidently resolved across the entire 3000–5000 m/z range. By leveraging the charge-resolving capabilities of DMT, we achieve separation of the homotetramers (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig3">Figure 3</a>B,C) and the 0, 1, and 2 ligand-bound states. The 2D plot clearly shows the gain in resolution achieved when charge is simultaneously measured with m/z by separating the 14+ and 15+ charge states for WT and CT, respectively, in the range 3900–4200 m/z. Additionally, using ion mobility does not provide the same kind of 2D resolution due to the similarity in arrival times for the homotetramer proteoforms, as evidenced by <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Figures S4 and S5</a> (see the Supporting Information). These data provide evidence that when ion mobility is able to separate out species that overlap in m/z yet differ in mobility, CDMS could be an alternative or used complementarily since the species likely also differ in charge.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Anal_Chem_2025_97_49_27057_27063_Figure_3_A_Mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_with_thyroxine_binding_61b1e98a94.jpg" alt="Anal. Chem. 2025, 97, 49, 27057–27063: Figure 3. (A) Mass spectra of WT-TTR and CT-TTR homotetramers with thyroxine binding. Ligand binding can be resolved, but homotetramers cannot be confidently identified. Charge states labeled are for WT; CT is always one charge state higher at the same m/z range. (B) DMT heatmap resolving WT-TTR and CT-TTR homotetramers with the additional measurement of charge. (C) Deconvoluted mass spectrum from DMT analysis. Both homotetramers and their ligand binding are resolved, and fit for analysis is shown in red. (D) Mole fraction of each homotetramer and their thyroxine binding species. Error bars represent the standard deviation of replicates (n = 3). The significance for each ligand state is in respect to the left adjacent state. *p &lt; 0.05." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Anal_Chem_2025_97_49_27057_27063_Figure_3_A_Mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_with_thyroxine_binding_61b1e98a94.jpg 181w," sizes="100vw" width="1266" height="1094"><h4>Conclusion</h4>This work demonstrates that quantitatively, Orbitrap-based CDMS/DMT can determine differences in protein-complex stability and ligand binding. By directly comparing WT- with CT-TTR, we show that the CT tag accelerates tetramer dissociation while enhancing T4 binding affinity. These results indicate that the C-terminus, located at the dimer–dimer interface, plays a more significant role in TTR stability and ligand recognition than previously appreciated. <a href="javascript:void(0);">(12)</a> Even the addition of a short peptide sequence perturbs noncovalent interactions at the interface, likely altering solvent accessibility, and the dynamics of the thyroxine binding channel. <a href="javascript:void(0);">(37,54)</a> Such findings underscore the importance of evaluating how seemingly minor sequence modifications, such as affinity tags, can influence fundamental biophysical properties.Beyond TTR, this work positions quantitative CDMS as a broadly applicable strategy for analyzing heterogeneous protein systems, where charge domain separation overcomes the resolution limits of m/z domain measurements in traditional nMS experiments. While much of the field has emphasized extending CDMS to ultrahigh masses and maximal resolution, <a href="javascript:void(0);">(16,18)</a> our results highlight the underexplored potential of applying the method in the 1000–10,000 m/z range common to nMS experiments. This capability is directly relevant to heterogeneous membrane protein complexes, which often display broad distributions of oligomeric states, PTMs, lipid, and ligand adducts that complicate spectra. <a href="javascript:void(0);">(48,55)</a> Similarly, mAbs can oligomerize and exhibit mass heterogeneity from variable glycosylation, affecting pharmacokinetics, effector function, and stability. <a href="javascript:void(0);">(19)</a> CDMS may resolve and quantify such proteoforms in a single experiment without the need for charge reduction or chemical derivatization. <a href="javascript:void(0);">(48,56,57)</a>

Dissecting Heterogeneous Populations of Protein-Complex Samples Using Direct Mass Technology

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KNAUER Eurospher II 100 Si (U)HPLC Columns for NP & HILIC (USP L3)

Unmodified Silica gel materials were the first ones used for chromatography. This is the reason the mode is called "normal phase" (NP).

Si columns for Normal Phase and HILIC applications (USP L3)Unmodified Silica gel materials were the first ones used for chromatography. This is the reason the mode is called "normal phase" (NP). They are still used in HPLC, although reversed phase (RP) is by far the most often used HPLC mode today.<h5>A wide range of porous Si materials are available, characterized by:</h5><ul><li>Surface area</li><li>Pore size</li><li>Particle size</li><li>Purity</li><li>Metal content</li></ul><h5>Properties</h5><ul><li>Separation mechanism: Hydrophilic interactions</li><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>No modification, no endcapping, with 0 % carbon content</li></ul><h5>Key features</h5><ul><li>High-class HPLC phase perfectly suited to take on routine analyses as well as the most ambitious chromatography tasks, outstanding mechanical and chemical stability.</li></ul><h5>Recommended application areas</h5><ul><li>Wide range of different applications, i.e. SEC (size exclusion chromatography) but also for normal phase HPLC and HILIC; good choice for analytical and preparative purposes to separate polar compounds.</li></ul><blockquote>Tip: Normal phase (NP) stationary phases have been the first phases for chromatography and that is why their properties of polarity were determined as ’’normal’’. The stationary phase of a NP column has polar properties and is commonly used with nonpolar solvents as hexane or heptane. The other way round a reversed phase (RP) column has covalent charcteristics and is used with more polar eluents, like mixtures of acetonitrile and water.</blockquote>Stationary phase Eurospher II 100 Si is provided in these column types: analytical, semi-preparative and preparative.Eurospher II 100 Si Analytical Columns are available with these parameters:<ul><li>Column length (mm): 50, 100, 150, 250</li><li>Column ID (mm): 3, 4, 4.6</li><li>Particle size (µm): 3, 5</li></ul>Eurospher II 100 Si Semi-Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 30, 50, 125, 150, 250</li><li>Column ID (mm): 8, 16</li><li>Particle size (µm): 5, 10</li></ul><h3>KNAUER (U)HPLC Columns</h3>Widest range of HPLC and UHPLC columns for all separation modes and applications.<ul><li>Safe Investment: Robust and reliable columns for attractive price&nbsp;</li><li>Separation Mode: Reversed Phase, HILIC, Normale</li><li>Simplicity: Easy purchase via our online store with fast delivery</li><li>Application: All-rounder for research or highly specialised for high-throughput analysis? We have the best column for your requirements.</li><li>Flexibility: Wide selection of column and particle sizes, for (U)HPLC applications up to 1000 bar</li></ul>KNAUER offers the perfect column for any small molecule separation. No matter which separation mode, molecule and the mobile phase, we offer a suitable (U)HPLC stationary phase. Choose from a wide range of modifications, particle sizes and column dimensions to suit your application. To elongate the lifetime of your column, you can choose to use a suitable precolumn.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_KNAUER_U_HPLC_C8_and_C8_A_Columns_083c60f401.webp" alt="KNAUER: KNAUER (U)HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_KNAUER_U_HPLC_C8_and_C8_A_Columns_083c60f401.webp 182w," sizes="100vw" width="787" height="674">

KNAUER Eurospher II Chiral AM Columns for NP & RP (USP L51)

Eurospher II Chiral AM uses the chiral selector Amylose-tris-(3,5 dimethylphenylcarbamate) and is equivalent to Chiralpak AD. 

Eurospher II Chiral AM uses the chiral selector Amylose-tris-(3,5 dimethylphenylcarbamate) and is equivalent to Chiralpak AD. KNAUER offers 2 different CPS versions: Eurospher II Chiral AM is designed for separations in normal phase (NP) mode and Eurospher II Chiral AM-R &nbsp;for separations in reversed phase (RP) mode.<h5>Properties</h5><ul><li>Silica gel: ultra pure, &gt; 99.99 %</li><li>Metal content: &lt; 10 ppm</li><li>Particle size: 3 μm, 5 μm, 10 μm</li><li>Particle form: spherical</li><li>Pore size of base material: 1000 Å</li><li>Chiral selector: Amylose-tris-(3,5-dimethylphenylcarbamate) for Chiral AM&nbsp;</li></ul><h5>Key features</h5><ul><li>KNAUER offers these chiral stationary phases for two different separation modes: Eurospher II Chiral AM is designed for separations in normal phase (NP) mode, Eurospher II Chiral AM-R for separations in reversed phase mode.</li></ul><h5>Recommended application areas</h5><ul><li>Eurospher II Chiral AM columns are able to separate neutral, acidic and basic racemates.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Chiral_AM_906d13b0b5.webp" alt="KNAUER: Eurospher II Chiral AM" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Chiral_AM_906d13b0b5.webp 245w," sizes="100vw" width="690" height="388"><blockquote>Stationary phase Eurospher II Chiral AM (AM-R) is provided in these column types: analytical, semi-preparative and preparative.</blockquote>Eurospher II Chiral AM and AM-R Analytical Columns are available with these parameters:<ul><li>Column length (mm): 50, 100, 150, 250</li><li>Column ID (mm): 4, 4.6</li><li>Particle size (µm): 3, 5, 10</li></ul>Eurospher II Chiral AM and AM-R Semi-Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 150, 250</li><li>Column ID (mm): 10</li><li>Particle size (µm): 5, 10</li></ul><h3>KNAUER Chiral HPLC Columns</h3>For analytical, preparative and SMB chiral separations<ul><li>Column Brand<ul><li>Eurospher II</li></ul></li><li>Reversed Phase Modifications<ul><li>Chiral NR-R</li><li>Chiral AM-R</li><li>Chiral OM-R</li></ul></li><li>Normal Phase Modifications<ul><li>Chiral NR</li><li>Chiral AM</li><li>Chiral OM</li></ul></li><li>Flexibility: Wide selection of column and particle sizes, for preparative and analytical applications</li><li>Expandable: Upscaling even for continuous SMB</li><li>Application Service: We offer a customized screening service for your analytes. You will receive an optimal column recommendation including the method parameters.</li></ul><h4>Eurospher II Chiral</h4>Based on ultra-high purity silica, the Eurospher II chiral column materials are characterized by high enantioselectivity and loadability.&nbsp;Available in a wide range of dimensions for analytical, preparative and SMB (simulated moving bed) applications, Eurospher II Chiral columns are the perfect choice for even the most challenging enantioseparation tasks&nbsp;Since chiral separations are not very well predictable, KNAUER offers a chiral screening service for your samples (Article number: AL0220).<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurospher_II_chiral_48c53afebe.jpg" alt="KNAUER: Eurospher II chiral" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurospher_II_chiral_48c53afebe.jpg 245w," sizes="100vw" width="1369" height="633"><blockquote>Tip: Some of the most popular eluents for HPLC (such as acetone, chloroform, DMF, DMSO, MEK, toluene, dioxane, ethyl acetate, methylene chloride, pyridine and THF) which may be remaining in your HPLC system, can destroy Eurospher II Chiral AM and OM phases even in small concentrations! It is highly recommended that the HPLC system is flushed with appropriate eluents before the installation of the chiral column.</blockquote>

KNAUER Eurospher II Chiral OM Columns for NP & RP (USP L40, USP L93)

Eurospher II Chiral OM uses the chiral selector Cellulose-tris-(3,5-dimethylphenylcarbamate) and is equivalent to Chiralcel OD. 

Eurospher II Chiral OM uses the chiral selector Cellulose-tris-(3,5-dimethylphenylcarbamate) and is equivalent to Chiralcel OD. KNAUER offers 2 different CPS versions: Eurospher II Chiral OM is designed for separations in normal phase (NP) mode and Eurospher II Chiral OM-R for separations in reversed phase (RP) mode.<h5>Properties</h5><ul><li>Silica gel: ultra pure, &gt; 99.99 %</li><li>Metal content: &lt; 10 ppm</li><li>Particle size: 3 μm, 5 μm, 10 μm</li><li>Particle form: spherical</li><li>Pore size of base material: 1000 Å</li><li>Chiral selector: Cellulose-tris-(3,5-dimethyl- phenylcarbamate) for Chiral OM</li></ul><h5>Key features</h5><ul><li>KNAUER offers these chiral stationary phases for two different separation modes: Eurospher II Chiral OM is designed for separations in normal phase (NP) mode, Eurospher II Chiral OM-R for separations in reversed phase mode.</li></ul><h5>Recommended application areas</h5><ul><li>Eurospher II Chiral OM columns are able to separate neutral, acidic and basic racemates.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Chiral_OM_c2a3f1a159.webp" alt="KNAUER: Eurospher II Chiral OM" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Chiral_OM_c2a3f1a159.webp 245w," sizes="100vw" width="690" height="388"><blockquote>Stationary phase Eurospher II Chiral OM (OM-R) is provided in these column types: analytical, semi-preparative and preparative.</blockquote>Eurospher II Chiral OM and OM-R Analytical Columns are available with these parameters:<ul><li>Column length (mm): 50, 100, 150, 250</li><li>Column ID (mm): 4, 4.6</li><li>Particle size (µm): 3, 5, 10</li></ul>Eurospher II Chiral OM and OM-R Semi-Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 150, 250</li><li>Column ID (mm): 10</li><li>Particle size (µm): 5, 10</li></ul><h3>KNAUER Chiral HPLC Columns</h3>For analytical, preparative and SMB chiral separations<ul><li>Column Brand<ul><li>Eurospher II</li></ul></li><li>Reversed Phase Modifications<ul><li>Chiral NR-R</li><li>Chiral AM-R</li><li>Chiral OM-R</li></ul></li><li>Normal Phase Modifications<ul><li>Chiral NR</li><li>Chiral AM</li><li>Chiral OM</li></ul></li><li>Flexibility: Wide selection of column and particle sizes, for preparative and analytical applications</li><li>Expandable: Upscaling even for continuous SMB</li><li>Application Service: We offer a customized screening service for your analytes. You will receive an optimal column recommendation including the method parameters.</li></ul><h4>Eurospher II Chiral</h4>Based on ultra-high purity silica, the Eurospher II chiral column materials are characterized by high enantioselectivity and loadability.&nbsp;Available in a wide range of dimensions for analytical, preparative and SMB (simulated moving bed) applications, Eurospher II Chiral columns are the perfect choice for even the most challenging enantioseparation tasks&nbsp;Since chiral separations are not very well predictable, KNAUER offers a chiral screening service for your samples (Article number: AL0220).<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurospher_II_chiral_48c53afebe.jpg" alt="KNAUER: Eurospher II chiral" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurospher_II_chiral_48c53afebe.jpg 245w," sizes="100vw" width="1369" height="633"><blockquote>Tip: Some of the most popular eluents for HPLC (such as acetone, chloroform, DMF, DMSO, MEK, toluene, dioxane, ethyl acetate, methylene chloride, pyridine and THF) which may be remaining in your HPLC system, can destroy Eurospher II Chiral AM and OM phases even in small concentrations! It is highly recommended that the HPLC system is flushed with appropriate eluents before the installation of the chiral column.</blockquote>

KNAUER Eurospher II Chiral NR Columns for NP & RP

Eurospher II Chiral NR is an immobilized brush-type phase with very broad generality and orhogonal selectivity to Eurospher II Chiral AM and OM.

Eurospher II Chiral NR is an immobilized brush-type phase with very broad generality and orhogonal selectivity to Eurospher II Chiral AM and OM. In many cases it is much more stable compared to Eurospher II Chiral AM or OM. The Chiral-NR selector is covalently bound, so that you can use all HPLC-eluents.Due to its high loadability it is perfectly suited for preparative separations. Both phases can be used in RP and NP mode. Eurospher II Chiral-NR-R shows reversed elution order compared to Eurospher II Chiral-NR caused by the modification with the opposite enantiomeric form of the chiral selector.<h5>Properties</h5><ul><li>Silica gel: ultra pure, &gt; 99.99 %</li><li>Metal content: &lt; 10 ppm</li><li>Particle size:&nbsp;<ul><li>Eurospher II Chiral NR: 3 μm, 5 μm, 8 µm, 12 µm</li><li>Eurospher II Chiral NR-R: 8 µm, 12 µm</li></ul></li><li>Particle form: spherical</li><li>Pore size of base material: 1000 Å</li></ul><h5>Recommended application areas</h5><ul><li>Eurospher II Chiral NR columns are able to separate analytes with an oxygen at or near the chiral center and additionally an aromatic ring.</li></ul><blockquote>Stationary phase Eurospher II Chiral NR (NR-R) is provided in these column types: analytical, semi-preparative and preparative.</blockquote>Eurospher II Chiral NR and NR-R Analytical Columns are available with these parameters:<ul><li>Column length (mm): 50, 100, 150, 250</li><li>Column ID (mm): 3, 4, 4.6</li><li>Particle size (µm): 3, 5, 8, 12</li></ul>Eurospher II Chiral NR and NR-R Semi-Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 150, 250</li><li>Column ID (mm): 8, 10</li><li>Particle size (µm): 8, 12</li></ul><h3>KNAUER Chiral HPLC Columns</h3>For analytical, preparative and SMB chiral separations<ul><li>Column Brand<ul><li>Eurospher II</li></ul></li><li>Reversed Phase Modifications<ul><li>Chiral NR-R</li><li>Chiral AM-R</li><li>Chiral OM-R</li></ul></li><li>Normal Phase Modifications<ul><li>Chiral NR</li><li>Chiral AM</li><li>Chiral OM</li></ul></li><li>Flexibility: Wide selection of column and particle sizes, for preparative and analytical applications</li><li>Expandable: Upscaling even for continuous SMB</li><li>Application Service: We offer a customized screening service for your analytes. You will receive an optimal column recommendation including the method parameters.</li></ul><h4>Eurospher II Chiral</h4>Based on ultra-high purity silica, the Eurospher II chiral column materials are characterized by high enantioselectivity and loadability.&nbsp;Available in a wide range of dimensions for analytical, preparative and SMB (simulated moving bed) applications, Eurospher II Chiral columns are the perfect choice for even the most challenging enantioseparation tasks&nbsp;Since chiral separations are not very well predictable, KNAUER offers a chiral screening service for your samples (Article number: AL0220).<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurospher_II_chiral_48c53afebe.jpg" alt="KNAUER: Eurospher II chiral" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurospher_II_chiral_48c53afebe.jpg 245w," sizes="100vw" width="1369" height="633"><blockquote>Tip: Some of the most popular eluents for HPLC (such as acetone, chloroform, DMF, DMSO, MEK, toluene, dioxane, ethyl acetate, methylene chloride, pyridine and THF) which may be remaining in your HPLC system, can destroy Eurospher II Chiral AM and OM phases even in small concentrations! It is highly recommended that the HPLC system is flushed with appropriate eluents before the installation of the chiral column.</blockquote>

KNAUER Eurokat H Ion Exclusion/Ligand Exchange Columns (USP L17)

The Eurokat H ionic form is especially designed for the analysis of organic acids and even complex mixtures of acids, sugars and alcohols as well as sugar alcohols.

Organic acids and alcoholsThe Eurokat H ionic form is especially designed for the analysis of organic acids and even complex mixtures of acids, sugars and alcohols as well as sugar alcohols. It is a cation exchange material with 8 % cross linkage of the styrenedivinylbenzene copolymer. Best results are acieved with aqueous eluents and small amounts of anorganic acids, recommended eluent 0.005 M sulfuric acid. The usage of up to 10 % organic content in the mobile phase is possible.<h5>Properties</h5><ul><li>Sulfonated cross-linked styrenedivinylbenzene copolymer phase for the determination of organic acids, carbohydrates and alcohols</li><li>H-form, 8 % cross linkage</li><li>Cation exchanger, extremly long lasting lifetime when correctly handled, best results with aqueous eluents and small amounts of anorganic acids, recommended eluent 0,01 N sulfuric acid, usage of up to 10 % organic content in the mobile phase is possible</li></ul><h5>Technical Data</h5><ul><li>Sulfonated cross-linked styrenedivinylbenzene copolymer with 8 % cross linkage in the ionic form H, available in 10 μm particle size, pressure stable up to maximum 100 bar</li></ul><h5>Recommended application areas</h5><ul><li>Eurokat H is especially designed for the analysis of organic acids and even complex mixtures of acids, sugars and alcohols as well as sugar alcohols. Due to a differing separation process we recommend the use of these type of columns only in 8 mm ID or 4 mm ID.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurokat_H_Chromatogram_e2c6665a1f.webp" alt="KNAUER: Eurokat H Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurokat_H_Chromatogram_e2c6665a1f.webp 245w," sizes="100vw" width="690" height="281"><blockquote>Tip: Eurokat columns are characterized by an extremely long lifetime if handled properly. Especially pressure shocks and organic solvent contents of more than 10 % in the mobile phase should be avoided absolutely.</blockquote><h3>KNAUER Ion Exclusion and Ligand Exchange Columns</h3>Separation of organic acids, carbohydrates, alcohols on sulfonated cross-linked styrenedivinylbenzene copolymer<ul><li>Modifications<ul><li>Eurokat H</li><li>Eurokat Ca</li><li>Eurokat Pb</li><li>Eurokat Na</li></ul></li><li>High Temperature Methods: Up to 90 °C</li><li>Method Development: Optional up to 10 % organic solvent</li><li>Chemically stable: pH 1–12</li><li>Sustainability: Aqueous eluents protect the environment and are cost-effectiv</li><li>User Friendly: Simple and robust methods for daily analysis. Versatile in its use.</li><li>Simplicity: Easy purchase via our online store with fast delivery.&nbsp;</li></ul><h4>Characteristics&nbsp;</h4>Eurokat high performance polymer phases were especially developed for the separation of organic acids, carbohydrates, alcohols and even complex mixtures of these compounds. Eurokat is a sulfonated cross-linked styrenedivinylbenzene copolymer available in several ionic forms (H, Ca and Pb). This particular cation exchanger is characterized by an outstanding density of functional groups, making it the ideal choice for your ion exclusion, size exclusion and ligand exchange chromatography.<h4>Choice of chromatographic conditions&nbsp;</h4>The Eurokat stationary phase is designed to be applicable to a wide range of diverse chromatographic conditions. All Eurokat columns can be used at temperatures up to 90 °C with no organic solvents. The best separation of sugars can be achieved using between 60 to 90 °C. To extend separation performance, it is possible to connect up to three columns of Eurokat in series. Eurokat columns require no organic solvents and thus are environmentally friendly.&nbsp;<h4>Stability&nbsp;</h4>Eurokat polymer columns are extremely stable over the whole pH range. This is one striking advantage compared with silica-based phases which have a limited lifetime at pH extremes, especially in the higher pH range. Most importantly, Eurokat phases show extraordinary column lifetime stability and are not affected by aqueous solvents.&nbsp;<h4>Application areas&nbsp;</h4><ul><li>Carbohydrates and organic acids in softdrinks and fruit juices&nbsp;</li><li>Sugar substitutes</li><li>Food preservatives</li><li>Dairy products</li><li>Urine analytic (Uric acid, Hippuric acid)</li><li>Monitoring of fermentation processes</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg" alt="KNAUER: Eurokat - Principle of ligand exchange mechanism" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg 245w," sizes="100vw" width="1382" height="570">

KNAUER Eurokat Pb & Ca Ion Exclusion/Ligand Exchange Columns (USP L34 / USP L19)

The ionic forms Ca and Pb are best suited for the analysis of smaller carbohydrates like mono- and disaccharides and sugars up to a degree of polymerization (DP) of 4. 

Analysis of mono- and disaccharidesThe ionic forms Ca and Pb are best suited for the analysis of smaller carbohydrates like mono- and disaccharides and sugars up to a degree of polymerization (DP) of 4. It is a cation exchange material with 6 % cross linkage of the styrenedivinylbenzene copolymer. Best results are achieved with aqueous eluents, recommended eluent is pure deionized water. The usage of up to 10 % organic content in the mobile phase is possible.<h5>Properties</h5><ul><li>Polymer phase for the determination of mono- and disaccharides</li><li>Pb (USP L34) form, 6 % cross linkage</li><li>Cation exchanger, extremely long lasting lifetime when correctly handled, best results with aqueous eluents, recommended eluent is pure deionized water, usage of up to 10 % organic content in the mobile phase is possible</li></ul><h5>Technical Data</h5><ul><li>Sulfonated cross-linked styrenedivinylbenzene copolymer with 6 % cross linkage in the ionic form Pb, available in 10μm particle size, pressure stable up to maximum 100 bar</li></ul><h5>Recommended application areas</h5><ul><li>Especially designed for the analysis of small carbohydrates up to DP 4</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurokat_Pb_Ca_Chromatogram_2054f70e49.webp" alt="KNAUER: Eurokat Pb &amp; Ca Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurokat_Pb_Ca_Chromatogram_2054f70e49.webp 245w," sizes="100vw" width="690" height="271"><blockquote>Tip: Eurokat columns are used at high temperatures. During equilibration it is very important to have an eye on the backpressure and to start with very low flow rates and increase them only slowly and stepwise after the column has adapted to the temperature.</blockquote><h3>KNAUER Ion Exclusion and Ligand Exchange Columns</h3>Separation of organic acids, carbohydrates, alcohols on sulfonated cross-linked styrenedivinylbenzene copolymer<ul><li>Modifications<ul><li>Eurokat H</li><li>Eurokat Ca</li><li>Eurokat Pb</li><li>Eurokat Na</li></ul></li><li>High Temperature Methods: Up to 90 °C</li><li>Method Development: Optional up to 10 % organic solvent</li><li>Chemically stable: pH 1–12</li><li>Sustainability: Aqueous eluents protect the environment and are cost-effectiv</li><li>User Friendly: Simple and robust methods for daily analysis. Versatile in its use.</li><li>Simplicity: Easy purchase via our online store with fast delivery.&nbsp;</li></ul><h4>Characteristics&nbsp;</h4>Eurokat high performance polymer phases were especially developed for the separation of organic acids, carbohydrates, alcohols and even complex mixtures of these compounds. Eurokat is a sulfonated cross-linked styrenedivinylbenzene copolymer available in several ionic forms (H, Ca and Pb). This particular cation exchanger is characterized by an outstanding density of functional groups, making it the ideal choice for your ion exclusion, size exclusion and ligand exchange chromatography.<h4>Choice of chromatographic conditions&nbsp;</h4>The Eurokat stationary phase is designed to be applicable to a wide range of diverse chromatographic conditions. All Eurokat columns can be used at temperatures up to 90 °C with no organic solvents. The best separation of sugars can be achieved using between 60 to 90 °C. To extend separation performance, it is possible to connect up to three columns of Eurokat in series. Eurokat columns require no organic solvents and thus are environmentally friendly.&nbsp;<h4>Stability&nbsp;</h4>Eurokat polymer columns are extremely stable over the whole pH range. This is one striking advantage compared with silica-based phases which have a limited lifetime at pH extremes, especially in the higher pH range. Most importantly, Eurokat phases show extraordinary column lifetime stability and are not affected by aqueous solvents.&nbsp;<h4>Application areas&nbsp;</h4><ul><li>Carbohydrates and organic acids in softdrinks and fruit juices&nbsp;</li><li>Sugar substitutes</li><li>Food preservatives</li><li>Dairy products</li><li>Urine analytic (Uric acid, Hippuric acid)</li><li>Monitoring of fermentation processes</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg" alt="KNAUER: Eurokat - Principle of ligand exchange mechanism" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg 245w," sizes="100vw" width="1382" height="570">

KNAUER Eurokat Na Ion Exclusion/Ligand Exchange Columns

The ionic form Na is best suited for the analysis of sugars oligomers up to a degree of polymerization (DP) of 8. 

Analysis of sugar oligomersThe ionic form Na is best suited for the analysis of sugars oligomers up to a degree of polymerization (DP) of 8. It is a cation exchange material with 6 % cross linkage of the styrenedivinylbenzene copolymer. Best results are achieved with aqueous eluents, recommended eluent is pure deionized water. The usage of up to 10 % organic content in the mobile phase is possible.&nbsp;<h5>Properties</h5><ul><li>Polymer phase for the determination of sugar oligomers</li><li>Na form, 6 % cross linkage</li><li>Cation exchanger, extremly long lasting lifetime when correctly handled, best results with aqueous eluents, recommended eluent is pure deionized water, usage of up to 10 % organic content in the mobile phase is possible</li></ul><h5>Technical Data</h5><ul><li>Sulfonated cross-linked styrenedivinylbenzene copolymer with 6 % cross linkage in the ionic form Na, available in 10 μm particle size, pressure stable up to maximum 100 bar</li></ul><h5>Recommended application areas</h5><ul><li>Especially designed for the analysis of sugar oligomers, separates carbohydrates up to DP 8</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurokat_Na_Chromatogram_7d3d81fa52.webp" alt="KNAUER: Eurokat Na Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurokat_Na_Chromatogram_7d3d81fa52.webp 188w," sizes="100vw" width="686" height="568"><blockquote>Tip: Eurokat columns are typically used with 100 % aqueous eluents. For storage, please avoid microbial growth by flushing the Eurokat column with 0.45 µm filtered ultrapure water and storing it at 4 °C.</blockquote><h3>KNAUER Ion Exclusion and Ligand Exchange Columns</h3>Separation of organic acids, carbohydrates, alcohols on sulfonated cross-linked styrenedivinylbenzene copolymer<ul><li>Modifications<ul><li>Eurokat H</li><li>Eurokat Ca</li><li>Eurokat Pb</li><li>Eurokat Na</li></ul></li><li>High Temperature Methods: Up to 90 °C</li><li>Method Development: Optional up to 10 % organic solvent</li><li>Chemically stable: pH 1–12</li><li>Sustainability: Aqueous eluents protect the environment and are cost-effectiv</li><li>User Friendly: Simple and robust methods for daily analysis. Versatile in its use.</li><li>Simplicity: Easy purchase via our online store with fast delivery.&nbsp;</li></ul><h4>Characteristics&nbsp;</h4>Eurokat high performance polymer phases were especially developed for the separation of organic acids, carbohydrates, alcohols and even complex mixtures of these compounds. Eurokat is a sulfonated cross-linked styrenedivinylbenzene copolymer available in several ionic forms (H, Ca and Pb). This particular cation exchanger is characterized by an outstanding density of functional groups, making it the ideal choice for your ion exclusion, size exclusion and ligand exchange chromatography.<h4>Choice of chromatographic conditions&nbsp;</h4>The Eurokat stationary phase is designed to be applicable to a wide range of diverse chromatographic conditions. All Eurokat columns can be used at temperatures up to 90 °C with no organic solvents. The best separation of sugars can be achieved using between 60 to 90 °C. To extend separation performance, it is possible to connect up to three columns of Eurokat in series. Eurokat columns require no organic solvents and thus are environmentally friendly.&nbsp;<h4>Stability&nbsp;</h4>Eurokat polymer columns are extremely stable over the whole pH range. This is one striking advantage compared with silica-based phases which have a limited lifetime at pH extremes, especially in the higher pH range. Most importantly, Eurokat phases show extraordinary column lifetime stability and are not affected by aqueous solvents.&nbsp;<h4>Application areas&nbsp;</h4><ul><li>Carbohydrates and organic acids in softdrinks and fruit juices&nbsp;</li><li>Sugar substitutes</li><li>Food preservatives</li><li>Dairy products</li><li>Urine analytic (Uric acid, Hippuric acid)</li><li>Monitoring of fermentation processes</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg" alt="KNAUER: Eurokat - Principle of ligand exchange mechanism" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg 245w," sizes="100vw" width="1382" height="570">

KNAUER Eurosil Bioselect 300 C4 HPLC Columns (USP L26)

Eurosil Bioselect C4 has been specifically developed for the determination and purification of peptides, proteins, and oligonucleotides up to a molecular weight of approximately 100 kDa. 

Analytical wide pore phase for the determination of biomolecules bigger than 20 kDaEurosil Bioselect C4 has been specifically developed for the determination and purification of peptides, proteins, and oligonucleotides up to a molecular weight of approximately 100 kDa. The optimized manufacturing process guarantees excellent batch–to-batch reproducibility. The Eurosil Bioselect sorbent is the first choice for Biochromatography with silica material.<h5>Properties</h5><ul><li>Ultra pure, spherical wide pore HPLC phase based on wide pore silica gel</li><li>Unpolar, monomeric C4 modification, endcapped</li><li>2 % carbon content (conventional endcapping)</li><li>Separation mechanism: hydrophobic and hydrophilic interaction</li></ul><figure class="image"><img style="aspect-ratio:200/400;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C4_3f3adfbdb4.webp" alt="KNAUER: C4" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C4_3f3adfbdb4.webp 78w," sizes="100vw" width="200" height="400"></figure><h5>Recommended application areas</h5><ul><li>Hydrophilic biomolecules and especially peptides larger than 10 000- 20 000 Da</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_Phases_98acc32d0e.jpg" alt="KNAUER: Eurosil Bioselect - Phases and recommended sizes of molecules" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_Phases_98acc32d0e.jpg 245w," sizes="100vw" width="1385" height="778"><h3>KNAUER Wide pore HPLC columns</h3>For enhanced resolution, capacity and recovery of proteins and other biomolecules<ul><li>Material: Silica or polymer particles</li><li>Separation Ranges: 2–100 kDa</li><li>Column Brands: Eurosil Bioselect or AppliChrom®</li><li>Particle sizes: 3–10 µm</li><li>Pore Sizes: 300 or 100–1000 Å</li><li>Specific surface: 90 ± 5 m2/g</li><li>Pore volume: 0.8 ml/g</li><li>Density: 450 g/l</li><li>Applications: Peptides exceeding approximately 50 amino acids and oligonucleotides greater than 25 residues</li><li>Customize: Bioanalysis requires a lot of flexibility in the pore size, the pH range, the temperatures and the solvents used. To achieve this, we cross phase limits.</li></ul><h4>Characteristics&nbsp;</h4><ul><li>Eurosil Bioselect columns are available in 4 modifications, useful for a wide range of separation tasks involving large molecules up to 100 000 Da.</li><li>Strict manufacturing procedures ensure a very narrow pore size distribution.</li><li>Interfering anions or heavy metal ions on the silica surface are not present in Eurosil Bioselect columns because only ultra pure silica gel and high quality chemical modifications are employed.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_85cfc2d201.jpg" alt="KNAUER: Eurosil Bioselect" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_85cfc2d201.jpg 222w," sizes="100vw" width="1114" height="782"><h4>Separation mechanism of Eurosil Bioselect</h4>To separate larger molecules, they need to freely access the interior of the pores of the packing material. Therefore, the analytes’ diameter must be smaller than the average pore diameter.&nbsp;For higher molecular weight solutes, the use of lower pore size materials (60-120 Å) as typically used for the analysis of small molecules may result restricted diffusion in the material´s pores and therewith reduced column efficiency.&nbsp;<h4>Modifications</h4>The recommended modification of Eurosil Bioselect depends on the molecular weight of the analytes.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_chemical_modifications_1fd5d87f7b.jpg" alt="KNAUER: Eurosil Bioselect - chemical modifications" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_chemical_modifications_1fd5d87f7b.jpg 245w," sizes="100vw" width="955" height="505"> &nbsp;

KNAUER Eurosil Bioselect 300 C8 HPLC Columns (USP L7)

Eurosil Bioselect C8 has been specifically developed for the determination and purification of peptides, proteins, and oligonucleotides up to a molecular weight of approximately 20 kDa.

Analytical wide pore phase for the determination of biomolecules bigger than 5000 DaEurosil Bioselect C8 has been specifically developed for the determination and purification of peptides, proteins, and oligonucleotides up to a molecular weight of approximately 20 kDa.<h5>Properties</h5><ul><li>Ultra pure, spherical wide pore HPLC phase based on wide pore silica gel</li><li>Unpolar, monomeric C8 modification, endcapped</li><li>4.5 % carbon content (conventional endcapping)</li><li>Separation mechanism: hydrophobic interaction</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C8_hydrosphob_6986c292b4.webp" alt="KNAUER: C8" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C8_hydrosphob_6986c292b4.webp 144w," sizes="100vw" width="381" height="413"><h5>Recommended application areas</h5><ul><li>Hydrophilic biomolecules, peptides, peptide mapping after enzymatic digestion</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_Phases_98acc32d0e.jpg" alt="KNAUER: Eurosil Bioselect - Phases and recommended sizes of molecules" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_Phases_98acc32d0e.jpg 245w," sizes="100vw" width="1385" height="778"><h3>KNAUER Wide pore HPLC columns</h3>For enhanced resolution, capacity and recovery of proteins and other biomolecules<ul><li>Material: Silica or polymer particles</li><li>Separation Ranges: 2–100 kDa</li><li>Column Brands: Eurosil Bioselect or AppliChrom®</li><li>Particle sizes: 3–10 µm</li><li>Pore Sizes: 300 or 100–1000 Å</li><li>Specific surface: 90 ± 5 m2/g</li><li>Pore volume: 0.8 ml/g</li><li>Density: 450 g/l</li><li>Applications: Peptides exceeding approximately 50 amino acids and oligonucleotides greater than 25 residues</li><li>Customize: Bioanalysis requires a lot of flexibility in the pore size, the pH range, the temperatures and the solvents used. To achieve this, we cross phase limits.</li></ul><h4>Characteristics&nbsp;</h4><ul><li>Eurosil Bioselect columns are available in 4 modifications, useful for a wide range of separation tasks involving large molecules up to 100 000 Da.</li><li>Strict manufacturing procedures ensure a very narrow pore size distribution.</li><li>Interfering anions or heavy metal ions on the silica surface are not present in Eurosil Bioselect columns because only ultra pure silica gel and high quality chemical modifications are employed.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_85cfc2d201.jpg" alt="KNAUER: Eurosil Bioselect" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_85cfc2d201.jpg 222w," sizes="100vw" width="1114" height="782"><h4>Separation mechanism of Eurosil Bioselect</h4>To separate larger molecules, they need to freely access the interior of the pores of the packing material. Therefore, the analytes’ diameter must be smaller than the average pore diameter.&nbsp;For higher molecular weight solutes, the use of lower pore size materials (60-120 Å) as typically used for the analysis of small molecules may result restricted diffusion in the material´s pores and therewith reduced column efficiency.&nbsp;<h4>Modifications</h4>The recommended modification of Eurosil Bioselect depends on the molecular weight of the analytes.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_chemical_modifications_1fd5d87f7b.jpg" alt="KNAUER: Eurosil Bioselect - chemical modifications" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_chemical_modifications_1fd5d87f7b.jpg 245w," sizes="100vw" width="955" height="505"> &nbsp;

KNAUER Eurosil Bioselect 300 C18 HPLC Columns (USP L1)

Eurosil Bioselect C18 has been specifically developed for the determination and purification of peptides, proteins, and oligonucleotides up to a molecular weigth of approximately 5 kDa.

Analytical wide pore phase for the determination of biomolecules bigger than 2000 Da​Eurosil Bioselect C18 has been specifically developed for the determination and purification of peptides, proteins, and oligonucleotides up to a molecular weigth of approximately 5 kDa.<h5>Properties</h5><ul><li>Ultra pure, spherical wide pore HPLC phase based on silica gel</li><li>Unpolar, monomeric C18 (Octadecyl) modification, endcapped</li><li>7.5 % carbon content (conventional endcapping)</li><li>Separation mechanism: hydrophobic interaction</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C18_Endcapped_standard_edd2523aca.webp" alt="KNAUER: C18 Endcapped standard" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C18_Endcapped_standard_edd2523aca.webp 234w," sizes="100vw" width="688" height="458"><h5>Recommended application areas</h5><ul><li>Hydrophilic biomolecules, peptides, peptide mapping after enzymatic digestion</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_Phases_98acc32d0e.jpg" alt="KNAUER: Eurosil Bioselect - Phases and recommended sizes of molecules" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_Phases_98acc32d0e.jpg 245w," sizes="100vw" width="1385" height="778"><blockquote>Tip: Caused by the larger pore size of 300 Å, Eurosil Bioselect phases are not as mechanical stable as classical silica gel phases with up to 150 Å and should not be used above 200 bar pressure.</blockquote><h3>KNAUER Wide pore HPLC columns</h3>For enhanced resolution, capacity and recovery of proteins and other biomolecules<ul><li>Material: Silica or polymer particles</li><li>Separation Ranges: 2–100 kDa</li><li>Column Brands: Eurosil Bioselect or AppliChrom®</li><li>Particle sizes: 3–10 µm</li><li>Pore Sizes: 300 or 100–1000 Å</li><li>Specific surface: 90 ± 5 m2/g</li><li>Pore volume: 0.8 ml/g</li><li>Density: 450 g/l</li><li>Applications: Peptides exceeding approximately 50 amino acids and oligonucleotides greater than 25 residues</li><li>Customize: Bioanalysis requires a lot of flexibility in the pore size, the pH range, the temperatures and the solvents used. To achieve this, we cross phase limits.</li></ul><h4>Characteristics&nbsp;</h4><ul><li>Eurosil Bioselect columns are available in 4 modifications, useful for a wide range of separation tasks involving large molecules up to 100 000 Da.</li><li>Strict manufacturing procedures ensure a very narrow pore size distribution.</li><li>Interfering anions or heavy metal ions on the silica surface are not present in Eurosil Bioselect columns because only ultra pure silica gel and high quality chemical modifications are employed.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_85cfc2d201.jpg" alt="KNAUER: Eurosil Bioselect" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_85cfc2d201.jpg 222w," sizes="100vw" width="1114" height="782"><h4>Separation mechanism of Eurosil Bioselect</h4>To separate larger molecules, they need to freely access the interior of the pores of the packing material. Therefore, the analytes’ diameter must be smaller than the average pore diameter.&nbsp;For higher molecular weight solutes, the use of lower pore size materials (60-120 Å) as typically used for the analysis of small molecules may result restricted diffusion in the material´s pores and therewith reduced column efficiency.&nbsp;<h4>Modifications</h4>The recommended modification of Eurosil Bioselect depends on the molecular weight of the analytes.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurosil_Bioselect_chemical_modifications_1fd5d87f7b.jpg" alt="KNAUER: Eurosil Bioselect - chemical modifications" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurosil_Bioselect_chemical_modifications_1fd5d87f7b.jpg 245w," sizes="100vw" width="955" height="505"> &nbsp;

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