EU Regulation 396/2005: Pesticide Residue Testing and the Critical Role of QuEChERS Evaporation in Food Safety

<div><div><p><strong>Researchers led by </strong><a target="_blank" rel="noopener noreferrer" href="https://kudova.group.uochb.cz/en"><strong>Eva Kudová</strong></a><strong> from IOCB Prague and Jitka Viktorová from UCT Prague have identified new androstane-based steroid derivatives that can significantly improve the effectiveness of existing antibiotics against multidrug-resistant </strong><i><strong>Staphylococcus aureus</strong></i><strong>.</strong></p></div></div><div><p>The team screened dozens of natural steroidal hormones and synthetic derivatives to see whether they could block bacterial efflux pumps – mechanisms that bacteria use to eject antibiotics and survive treatment. Two compounds emerged as particularly promising: they inhibited efflux pumps and lowered the effective doses of antibiotics such as ciprofloxacin and erythromycin.</p><p>Further analysis showed that one of the compounds also suppressed genes linked to bacterial virulence. Another key finding is that the most active molecules are non-toxic to human immune cells and showed no detectable endocrine activity, suggesting a favorable safety profile.</p><p>These findings support the idea that rationally designed steroid-based molecules could act as antibiotic adjuvants, helping existing drugs overcome bacterial resistance.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/IOCB_Prague_Steroidal_hormones_and_neurosteroids_novel_therapeutic_strategies_in_bacterial_infections_8e5d2a7b48.jpg" alt="IOCB Prague: Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_IOCB_Prague_Steroidal_hormones_and_neurosteroids_novel_therapeutic_strategies_in_bacterial_infections_8e5d2a7b48.jpg 222w," sizes="100vw" width="1258" height="886"></p><blockquote><h4><strong>Original Article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.sciencedirect.com/science/article/pii/S0223523426001613?via%3Dihub"><strong>Steroidal hormones and neurosteroids - novel therapeutic strategies in bacterial infections: Design, synthesis, and biological evaluation</strong></a></h4><p>Daniela Brdová, Bára Křížkovská, Jan Špaček, Zdeněk Míchal, Eva Jablonská, Ondřej Strnad, Hana Chodounská, Eszter Szánti-Pintér, Marina Morozovová, Václav Hanžl, Jan Tkadlec, Martijn Riool, Jan Lipov, Jitka Viktorová, Eva Kudová&nbsp;</p><p><i><strong>Eur. J. Med. Chem., 2026, 308, 118716</strong></i></p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1016/j.ejmech.2026.118716">https://doi.org/10.1016/j.ejmech.2026.118716</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><h4><strong>Abstract</strong></h4><p>The global rise of antibiotic resistance necessitates novel therapeutic strategies for infectious diseases. Inhibition of bacterial efflux pumps, which contribute to multidrug resistance, represents a promising approach to restore or even increase the efficacy of existing antibiotics. Using fluorescence-based ethidium bromide accumulation, broth microdilution, and checkerboard assays, we evaluated 26 endogenous steroidal hormones and neurosteroids, along with 30 synthetic derivatives, for their ability to enhance antibiotic susceptibility in multidrug-resistant <i>Staphylococcus aureus</i>. Structure-activity relationship analysis identified compounds <strong>13</strong> and <strong>16</strong> as lead candidates, exhibiting strong efflux pump inhibition and marked reductions in the minimum inhibitory concentrations of ciprofloxacin and erythromycin. Both compounds showed additive effects in checkerboard assays. Modifications at C-3 (polar substitution) and C-17 (3α,5β-stereochemistry and nonpolar substitution) were essential for potent efflux inhibition and sensitization, although these modifications were not additive when combined. Transcriptome analysis further revealed that compound <strong>13</strong> significantly downregulated <i>S. aureus</i> virulence-associated genes when administered alone or in combination with antibiotics. Cytotoxicity assessment in human peripheral blood mononuclear cells and receptor transactivation assays for estrogen, androgen, and progesterone receptors indicated that the most active derivatives were non-toxic and lacked detectable endocrine activity, suggesting a favorable safety profile. Overall, these findings support the concept that rationally designed andostane-based steroidal scaffolds can function as competitive bacterial efflux pump inhibitors and serve as potential antibiotic adjuvants to mitigate efflux-mediated resistance.</p><h4><strong>Instrumentation</strong></h4><h5><strong>Structural characterization</strong></h5><ul><li><strong>AVANCE III 400 MHz NMR spectrometer</strong> (Bruker)</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=3&amp;search=LTQ+Orbitrap+XL"><strong>LTQ Orbitrap XL HRMS</strong></a> (Thermo Fisher Scientific, ESI)</li></ul></div>

Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections

<p><strong>Metformin is currently the first-line oral drug of choice for the treatment of type 2 diabetes. It reduces glucose production in the liver, improves tissue sensitivity to insulin, and does not cause weight gain or hypoglycemia, which sets it apart from some other antidiabetic drugs. Moreover, its long-term beneficial effects on the risk of cardiovascular complications and mortality in people with type 2 diabetes have been well established. Researchers from the Institute of Physiology CAS (IPHYS) have identified a new group of blood metabolites that could help physicians objectively monitor whether patients with type 2 diabetes are taking their metformin as prescribed.</strong></p><h4><strong>New biomarkers for metformin use</strong></h4><p>A team led by Tomáš Čajka from the Laboratory of Translational Metabolism at IPHYS analyzed plasma samples from <strong>637 patients with type 2 diabetes treated with metformin</strong> and <strong>143 non-diabetic controls</strong> using advanced metabolomics and lipidomics. Among 614 detected metabolites, they identified five from the group of <strong>N-lactoyl-amino acids </strong>(e.g. N‑lactoyl-phenylalanine), which had previously been seen as unknown signals due to missing reference spectra in databases. The levels of these metabolites in the blood closely reflected the plasma concentrations of metformin. In patients with the highest metformin exposure, the concentrations of these metabolites were up to 7.2 times higher than in controls.</p><h4><strong>A sensitive “fingerprint” of the drug’s effect</strong></h4><p>N-Lactoyl-amino acids are formed in cells by combining lactate and amino acids, thus reflecting the metformin-induced changes in cellular energy metabolism. “<i>Importantly, even though they occur in plasma only at nanomolar concentrations, they reliably distinguish patients who take metformin regularly from those who take it irregularly or not at all</i>,” emphasizes T. Čajka.</p><h4><strong>Metabolomics in practice and international collaboration</strong></h4><p>The study also provides a detailed description of broader metabolic changes in type 2 diabetes, including increases in lactate, organic acids, and branched-chain amino acids, as well as extensive remodelling of the lipid profile. In addition to T. Čajka’s team, collaborators from the Institute for <strong>Clinical and Experimental Medicine in Prague</strong> and the <strong>West Coast Metabolomics Center</strong> (University of California, Davis) also participated in the study.</p><p>The results demonstrate that advanced metabolomics approaches developed at IPHYS within the <strong>CarDia project</strong> can find highly practical applications both in clinical studies and in personalized monitoring of treatment in patients with diabetes.</p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://ascpt.onlinelibrary.wiley.com/doi/10.1002/cpt.70205"><strong>Untargeted Metabolomics Identifies N-Lactoyl-Amino Acids as Dose-Responsive Plasma Biomarkers of Metformin Adherence in Type 2 Diabetes</strong></a></h4><p>Tomas Cajka, Jiri Hricko, Lucie Rudl Kulhava, Michaela Paucova, Michaela Novakova, Veronika Hola, Stanislava Rakusanova, Oliver Fiehn, Vojtech Skop, Ivana Lankova, Iva Miskova, Terezie Pelikanova, Martin Haluzik</p><p>Clin Pharmacol Ther, 119: 1057-1069</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1002/cpt.70205">https://doi.org/10.1002/cpt.70205</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><h4><strong>Abstract</strong></h4><p>Metformin is the most widely prescribed antidiabetic drug, yet adherence remains difficult to objectively assess. Using untargeted metabolomics and lipidomics, we analyzed plasma from 637 patients with type 2 diabetes (T2D) with confirmed metformin use and 143 nondiabetic controls, annotating 614 metabolites. Patients were stratified by plasma metformin into sub-therapeutic, therapeutic, and supra-therapeutic groups, and associations were evaluated by multiple linear regression and composite metabolite ranking. Five previously unannotated features were structurally identified as N-lactoyl-amino acids, whose levels correlated strongly with plasma metformin (ρ = 0.42–0.55, P &lt; 0.0001) and increased up to 7.2-fold in the supra-therapeutic group (&gt; 2000 ng/mL). While N-lactoyl-amino acids were consistently detected in the nanomolar range, they still displayed robust and dose-dependent associations with metformin. Broader metabolic changes in T2D included elevated lactate, organic acids, and branched-chain amino acids, together with reduced urea cycle metabolites. Lipidomics showed increases in saturated triacylglycerols and diacylglycerols and decreases in cholesteryl esters, sphingomyelins, and phospholipids. These findings establish N-lactoyl-amino acids as robust, dose-responsive plasma biomarkers of metformin exposure. Despite being up to four orders of magnitude less abundant than their amino acid precursors, they sensitively reflect mitochondrial lactate overflow and pharmacodynamic adaptation, offering objective assessment of adherence.</p>

New blood biomarkers reveal how faithfully diabetes patients take metformin

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The Czech Academy of Sciences (CAS) was established by Act No. 283/1992 Coll. as the Czech successor of the former Czechoslovak Academy of Sciences. It is set up as a complex of 54 public research institutions.

Czech Academy of Sciences

The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) is a leading scientific institution in the Czech Republic, recognized internationally. Its primary mission is basic research in the fields of chemical biology and medicinal chemistry, organic and material oriented chemistry, chemistry of natural compounds, biochemistry and molecular biology, physical chemistry, theoretical chemistry, and analytical chemistry. 

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences

Organomation, founded in 1959, designs and manufactures high-quality nitrogen evaporators and extraction systems. Known for innovation and durability, their lab instruments are used globally for efficient sample preparation with strong customer support.

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Waters/Wyatt DAWN™ Multi Angle Light Scattering (MALS) Detector

The world's most advanced light scattering instrument for absolute characterization of proteins, conjugates, macromolecules, and nanoparticles.

<h5><strong>Premier MALS</strong></h5><p>The DAWN instrument is the premier Multi-Angle static Light Scattering (MALS) detector for absolute characterization of the molar mass and size of macromolecules and nanoparticles in solution. It offers the highest sensitivity, the widest range of molecular weight, size, and concentration, and the largest selection of configurations and optional modules for enhanced capabilities.</p><h5><strong>Separation First</strong></h5><p>MALS is most often used in conjunction with a separation system such as Gel Permeation Chromatography (GPC-MALS), Size Exclusion Chromatography (SEC-MALS), or Field-Flow Fractionation (FFF-MALS) to determine distributions of mass, size, and composition, independent of column calibration by reference standards.</p><h5><strong>Supported by ASTRA ™ &nbsp;Software</strong></h5><p>ASTRA Software and its built-in analysis modules support the DAWN MALS instrument, providing the most versatile analysis available for online multi-angle and dynamic light scattering measurements.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Waters_DAWN_MALS_HPLC_detektor_konfigurace_d5b83e46b2.jpg" alt="Waters DAWN™ Multi Angle Light Scattering (MALS) Instrument: ASTRA Software" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Waters_DAWN_MALS_HPLC_detektor_konfigurace_d5b83e46b2.jpg 245w," sizes="100vw" width="1500" height="807"></p><h4><strong>Product description</strong></h4><p>The DAWN and its companion <strong>Optilab ™ &nbsp;dRI detector</strong> are the established benchmarks for MALS analysis, cited in thousands of peer-reviewed publications. Multi-angle light scattering detection is indispensable for use with <strong>GPC</strong> and <strong>HPLC-SEC </strong>in order to obtain reliable molecular mass distributions and information on molecular conformation, branching ratio, fragments and aggregates.</p><p><strong>SEC-MALS</strong> with a <strong>DAWN</strong> and <strong>Optilab</strong> characterizes conformation and branching of synthetic and natural <strong>polymers larger than 10 nm</strong> in rms radius R g . The addition of a <strong>ViscoStar ™&nbsp;</strong> differential viscometer creates a GPC triple-detection system that can analyze molecular conformation and size below the R g &nbsp;limit of 10 nm and determine Mark-Houwink Sakurada coefficients.</p><p>The combination of a UV/Vis absorbance detector with a DAWN instrument and Optilab refractive index detector creates a UV-MALS-RI triple-detection system, for analysis of copolymers and protein conjugates (glycoproteins, PEGylated proteins, surfactant-bound membrane proteins, etc.). With the addition of a <strong>WyattQELS ™ &nbsp;DLS module</strong> for size determination, protein conformation may be analyzed.</p><ul><li><i>M<sub>w</sub></i> &nbsp;from 200 Da to 1000 MDa</li><li><strong>Sensitivity:</strong> 10 ng/mL 100 kDa polystyrene in THF, 0.4 µg/mL BSA (66.4 kDa) in PBS</li><li><i>R<sub>g</sub></i> &nbsp;from 10 to 500 nm, up to 1000 nm with shape-specific models</li><li>Ultra-stable, high-power laser</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Waters_DAWN_MALS_HPLC_detektor_konfigurace_1_98811a1e87.jpg" alt="Waters DAWN™ Multi Angle Light Scattering (MALS) Instrument: Accessories" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Waters_DAWN_MALS_HPLC_detektor_konfigurace_1_98811a1e87.jpg 213w," sizes="100vw" width="1000" height="733"></p><p>The DAWN may also be used in batch (off-line) mode to characterize the weight-average molar mass, z-average size and second virial coefficient of unfractionated samples.</p><p>In conjunction with a <strong>Calypso ™ &nbsp;CG-MALS system</strong>, the DAWN characterizes macromolecular interactions, label-free and immobilization-free: affinity and absolute stoichiometry of self- and hetero-association of simple or complex molecular systems. The Calypso system also automates the determination of second virial coefficients, cross virial coefficients, average molar masses and sizes.</p><h5><strong>Ultrasonic Cleaning Included</strong></h5><p>Each DAWN instrument includes an embedded <strong>COMET ™ &nbsp;ultrasonic transducer</strong> that cleans the flow cell automatically by agitating the fluid and loosening particles from the glass surfaces.</p><h5><strong>Temperature-Controlled Models</strong></h5><ul><li>Ambient model</li><li>Ultra-High-Temperature (UHT) model, from ambient up to +210 °C</li><li>Standard Peltier heated/cooled (H/C) model, temperature control from -15 °C to +150 °C</li></ul><h4><strong>Specifications</strong></h4><h5><strong>Measurement Capabilities</strong></h5><ul><li><strong>Molar Mass Range:</strong> From 200 Da to 1 GDa, depending on dn/dc, sample concentration, and chromatography conditions.</li><li><strong>Molecular Size (Radius of Gyration, Rg):</strong> Approximately 10 nm to 500 nm, extendable to 1000 nm with shape-specific models.</li><li><strong>Hydrodynamic Radius (Rh):</strong><ul><li><strong>Flow mode:</strong> 0.5 nm to 300 nm (depending on configuration and flow rate).</li><li><strong>Batch mode:</strong> 0.5 nm to 1 µm (requires WyattQELS™ DLS module or DynaPro™ NanoStar™ with fiber optic connection).</li></ul></li><li><strong>Sensitivity:</strong> Detects as little as 10 ng of 100 kDa polystyrene in THF or 200 ng of BSA in PBS, using a standard 7.8 mm x 300 mm SEC column and no post-column filter.</li></ul><h5><strong>Fluidics and Compatibility</strong></h5><ul><li><strong>Mobile Phase:</strong> Compatible with both aqueous and organic solvents.</li><li><strong>Wetted Materials:</strong> 316 stainless steel, fused silica or F2 glass, and Kalrez.</li></ul><h5><strong>Optical System and Detectors</strong></h5><ul><li><strong>MALS Detectors:</strong> 18 photodiodes with high gain and wide dynamic range for multi-angle light scattering.</li><li><strong>Auxiliary Detectors:</strong><ul><li>Laser monitor for stabilization</li><li>Forward transmission monitor to improve data quality and correct for sample absorption</li></ul></li><li><strong>Dynamic Range:</strong> 3,300,000:1</li><li><strong>Optional DLS Detection:</strong><ul><li>Integrated WyattQELS™ module inside the DAWN</li><li>External fiber optic connection with DynaPro NanoStar or Mobius DLS-ELS instruments</li></ul></li></ul><h5><strong>Laser Specifications</strong></h5><ul><li><strong>Wavelength:</strong> Standard 658 nm ± 4 nm; optional 785 nm for fluorescent samples</li><li><strong>Power Control:</strong> Programmable from 10% to 100%</li></ul><h5><strong>Flow Cell Options</strong></h5><ul><li><strong>Fused Silica:</strong> Ideal for solvents with refractive index &lt; 1.50</li><li><strong>F2 Glass:</strong> Recommended for solvents with refractive index &gt; 1.50</li></ul><h5><strong>Temperature Control Options</strong></h5><ul><li><strong>Ambient operation</strong></li><li><strong>Heated/Cooled (HC):</strong> -15 °C to +150 °C</li><li><strong>Ultra-High Temperature (UHT):</strong> Ambient to +210 °C</li></ul><h5><strong>Electronics and Connectivity</strong></h5><ul><li><strong>Analog Inputs:</strong> 4 differential inputs, 24-bit resolution, range -10 V to +10 V</li><li><strong>Analog Outputs:</strong> 2 outputs from selectable measurement channels, -10 V to +10 V</li><li><strong>I/O Options:</strong> Alarm in/out, auto-inject control, and Orbit™ valve integration</li><li><strong>Computer Interface:</strong> Ethernet</li><li><strong>Display:</strong> 10.1” high-resolution capacitive touchscreen with multi-touch controls</li></ul><h5><strong>Instrument Dimensions</strong></h5><ul><li><strong>Size:</strong> 58 cm (L) x 36 cm (W) x 26 cm (H)</li></ul><h4><strong>Other MALS Instruments</strong></h4><ul><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1115"><strong>miniDAWN™</strong></a> &nbsp;- Second only to the DAWN in sensitivity. Incorporates detectors at 3 angles to determine molar masses from 200 Da to 10 MDa and radii from 10 – 50 nm. Ambient only.</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1116"><strong>microDAWN™</strong></a><strong>&nbsp;</strong> - The first MALS detector for UHPLC, with interdetector dispersion as low as 1.5 µL. Incorporates detectors at 3 angles to determine molar masses from 200 Da to 20 MDa and radii from 10 – 50 nm. Ambient only.</li><li><strong>ultraDAWN™</strong> &nbsp;- Measures multi-angle light scattering and reports the results – weight-average molecular weight <i>M<sub>w</sub></i> &nbsp;and rms radius <i>R<sub>g</sub></i> &nbsp;– in real time.</li></ul>

Waters/Wyatt miniDAWN™ Multi Angle Light Scattering (MALS) Detector

The Best in Basic Multi-Angle Light Scattering for Absolute Macromolecular Analysis.

<h4><strong>Overview</strong></h4><h5><strong>Molar Mass</strong></h5><p>The miniDAWN determines absolute molar mass and size to characterize proteins, peptides, small polymers and nanoparticles in solution. Coupled to size exclusion chromatography (SEC or GPC), it eliminates the uncertainty and hassle of column calibration, for true confidence in macromolecular characterization.</p><h5><strong>Superb Sensitivity</strong></h5><p>The miniDAWN not only offers superb sensitivity—it further enhances productivity thanks to greatly enhanced field serviceability and easy data analysis with <strong>One-Click </strong><i><strong>M<sub>w</sub></strong></i><strong>™</strong> .</p><h5><strong>Compatible with ASTRA™&nbsp;</strong></h5><p>The miniDAWN is accompanied by <strong>ASTRA,</strong> the most versatile software package available for analysis of online multi-angle and dynamic light scattering. ASTRA and the miniDAWN incorporate advanced ease-of-use features that help guarantee excellent measurements with a single click.</p><h4><strong>Product Description</strong></h4><h5><strong>Molar mass, absolutely</strong></h5><p>Wyatt's miniDAWN is most often used in conjunction with size exclusion chromatography (SEC-MALS) or field-flow fractionation (FFF-MALS) to determine distributions of molecular weight, size and composition. No need to make assumptions about molecular conformation or ideal column interactions.</p><h5><strong>Characterize:</strong></h5><ul><li>Proteins, small peptides and oligonucleotides</li><li>Synthetic and natural polymers</li><li>Nanoparticles, virus-like particles and vesicles</li></ul><h5><strong>Measurement Range:</strong></h5><ul><li>MW from 200 Da to 10 MDa</li><li><i>r<sub>g</sub></i> &nbsp;from 10 to 50 nm, up to 150 nm with shape-specific models</li><li>sensitivity down to 25 ng of 100 kDa polystyrene in THF, injected on a standard GPC column</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Waters_Mini_DAWN_urcuje_molekulovou_hmotnost_nezavisle_na_kalibraci_kolony_Zde_MALS_ukazuje_ze_nejdrive_eluujici_molekula_nema_nejvyssi_molarni_hmotnost_509e5530ea.jpg" alt="Waters: The miniDAWN determines molecular weight independently of column calibration. Here MALS shows that the earliest-eluting molecule does not have the highest molar mass." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Waters_Mini_DAWN_urcuje_molekulovou_hmotnost_nezavisle_na_kalibraci_kolony_Zde_MALS_ukazuje_ze_nejdrive_eluujici_molekula_nema_nejvyssi_molarni_hmotnost_509e5530ea.jpg 245w," sizes="100vw" width="820" height="438"></p><p>The miniDAWN's performance is exceeded only by the <strong>DAWN™</strong> which covers a wider range of size and molecular weight, with even better sensitivity and additional optional modules.</p><h5><strong>Ultrasonic Cleaning Included</strong></h5><p>Each miniDAWN includes an embedded <strong>COMET™ ultrasonic transducer</strong> that cleans the flow cell automatically by agitating the fluid and loosening particles from the glass surfaces.</p><h5><strong>Modularity = Productivity</strong></h5><p>The miniDAWN incorporates a fully modular design. Each module can be tested independently by the software to verify that it is functioning correctly. This imparts nearly complete field serviceability, since malfunctioning modules can be replaced and validated on-site by service engineers with no further calibration or alignment.</p><p>The miniDAWN is also field-upgradeable: the embedded <strong>WyattQELS™ DLS Module </strong>for measuring hydrodynamic radii from 0.5 to 50 nm can be installed on-site as well as in new units shipped from the factory.</p><h5><strong>Not just SEC-MALS...</strong></h5><p>Wyatt's miniDAWN may be used in batch (off-line) mode or in conjunction with a <strong>Calypso™ CG-MALS system</strong> for characterization of average solution properties as well as macromolecular interaction properties including protein-protein binding affinity and complex stoichiometry.</p><h5><strong>Simplicity personified</strong></h5><p>With miniDAWN and <strong>ASTRA™</strong>, SEC-MALS became a whole lot easier. Sample-specific methods are set up in three short steps with ASTRA's Method Wizard, and new capabilities for automatic data processing mean that it takes just one click from your sample to a full report of the molecular weight and size results.</p><p>The miniDAWN's System Ready monitor will even let you know when the system is fully equilibrated with low baseline noise, ready to run.</p><h4><strong>Specifications</strong></h4><h5><strong>Measurement Capabilities</strong></h5><ul><li><strong>Molar Mass Range:</strong><br>200 Da to 10 MDa for proteins; up to 1 MDa for linear polymers (depending on dn/dc, sample concentration, and chromatography conditions).</li><li><strong>Molecular Size (Radius of Gyration, Rg):</strong><br>Approximately 10 nm to 50 nm, extendable up to 150 nm with shape-specific modeling.</li><li><strong>Hydrodynamic Radius (Rh):</strong><ul><li><strong>Flow mode:</strong> 0.5 nm to 50 nm (optimal at flow rates ≤ 0.3 mL/min)</li><li><strong>Batch mode:</strong> 0.5 nm to 1 µm (requires WyattQELS™ module or DynaPro™ NanoStar™ with fiber optic connection)</li></ul></li><li><strong>Sensitivity:</strong><br>Detects as little as 25 ng of 100 kDa polystyrene in THF or 500 ng of BSA in PBS using a standard 7.8 mm x 300 mm SEC column with no post-column filter.</li></ul><h5><strong>Fluidics and Compatibility</strong></h5><ul><li><strong>Mobile Phase Compatibility:</strong><br>Compatible with both aqueous and organic solvents.</li><li><strong>Wetted Materials:</strong><br>316 stainless steel, fused silica, and Kalrez.</li></ul><h5><strong>Optical System and Detectors</strong></h5><ul><li><strong>MALS Detectors:</strong><br>Three high-gain, high dynamic range photodiodes at fixed angles.</li><li><strong>Auxiliary Detectors:</strong><ul><li>Laser monitor for stability control</li><li>Forward transmission monitor for absorbing samples and data quality evaluation</li></ul></li><li><strong>Dynamic Range:</strong><br>3,300,000:1</li><li><strong>Optional DLS Detection:</strong><ul><li>Integrated WyattQELS™ module within the miniDAWN chassis</li><li>External fiber optic connection from DynaPro™ NanoStar or Mobius™ DLS-ELS instruments</li></ul></li></ul><h5><strong>Laser Specifications</strong></h5><ul><li><strong>Wavelength:</strong><br>658 nm ± 4 nm</li><li><strong>Power Control:</strong><br>Programmable from 10% to 100%</li></ul><h5><strong>Temperature Control</strong></h5><ul><li><strong>Sample Temperature:</strong> Ambient</li></ul><h5><strong>Electronics and Connectivity</strong></h5><ul><li><strong>Analog Inputs:</strong><br>2 differential inputs, 24-bit resolution, ±10 V range</li><li><strong>Analog Outputs:</strong><br>1 output from a selectable measurement channel, ±10 V range</li><li><strong>I/O Ports:</strong><br>Alarm in/out, auto-inject control, Orbit™ recycle valve support</li><li><strong>Computer Interface:</strong><br>Ethernet</li><li><strong>Data Rate:</strong><br>Up to 36.6 Hz</li></ul><h5><strong>User Interface and Display</strong></h5><ul><li><strong>Front Panel:</strong><br>7” (178 mm) high-resolution multi-touch display for real-time signal viewing, diagnostics, and settings</li></ul><h5><strong>Instrument Dimensions</strong></h5><ul><li><strong>Size:</strong> 58 cm (L) x 36 cm (W) x 18 cm (H)</li></ul><h4><strong>Other MALS Instruments</strong></h4><ul><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1114"><strong>DAWN™</strong></a> - The most sensitive MALS detector available, anywhere. Incorporates detectors at 18 angles to determine molar masses from 200 Da to 1 GDa and radii from 10 – 500 nm.<ul><li>Standard option: ambient temperature</li><li>Heated/cooled option: -15 °C to +150 °C</li><li>High-temperature option: ambient to +210 °C</li><li>The DAWN offers special options to handle fluorescent samples: fluorescence-blocking filters and an infrared, 785 nm laser.</li></ul></li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1116"><strong>microDAWN™</strong></a><strong> </strong>- The first MALS detector for UHPLC, with interdetector dispersion as low as 1.5 µL. Incorporates detectors at 3 angles to determine molar masses from 200 Da to 20 MDa and radii from 10 – 50 nm. Ambient only.</li><li><strong>ultraDAWN™</strong> - Measures multi-angle light scattering and reports the results – weight-average molecular weight <i>M<sub>w</sub></i> &nbsp;and rms radius <i>R<sub>g</sub></i> &nbsp;– in real time.</li></ul>

Waters/Wyatt microDAWN™ Multi Angle Light Scattering (MALS) Detector

The microDAWN can be coupled to any UHPLC-SEC system to determine absolute molecular weights and sizes of polymers, peptides, or proteins directly, without resorting to column calibration or reference standards.

<h4><strong>Overview</strong></h4><h5><strong>UHPLC-SEC System</strong></h5><p>The microDAWN can be coupled to any UHPLC-SEC system to determine absolute molecular weights and sizes of polymers, peptides, or proteins directly, without resorting to column calibration or reference standards. The microDAWN produces minimal band broadening in order to maintain the narrow peaks typical of UHPLC, while meeting or exceeding the sensitivity of the <strong>miniDAWN™</strong>.</p><h4><strong>Product Description</strong></h4><p>The <strong>microDAWN MALS detector</strong> performs absolute characterization of macromolecules eluting from UHPLC, determining molar mass and size <i>independently </i>of retention time and molecular reference standards. This instrument offers superb sensitivity over a wide range of molar mass, size and concentrations. In most respects the microDAWN is similar to the well-established <strong>miniDAWN™</strong>, a workhorse MALS instrument used in hundreds of labs around the world for characterizing proteins and other molecules smaller than 50 nm in radius.</p><p>Distinctly from the miniDAWN, the <strong>microDAWN</strong> is uniquely <strong>suitable for use in conjunction with UHPLC Size Exclusion Chromatography (SEC-MALS)</strong> thanks to its small interdetector dispersion. In some cases it may be used with ion-exchange or other types of chromatography. Regardless of the specifics, the microDAWN produces minimal band broadening in order to maintain the narrow peaks typical of UHPLC.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Waters_micro_DAWN_MALS_HPLC_detektor_konfigurace_1_4e888650cf.jpg" alt="Waters microDAWN™ Multi Angle Light Scattering (MALS) Instrument: Experimental setup" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Waters_micro_DAWN_MALS_HPLC_detektor_konfigurace_1_4e888650cf.jpg 229w," sizes="100vw" width="894" height="609"></p><ul><li><i>M<sub>w</sub>&nbsp;</i> from 200 Da to 10 MDa</li><li><strong>Sensitivity:</strong> 1.0 µg/mL BSA (66.4 kDa) in PBS; 50 ng/mL 100 kDa polystyrene in THF.</li><li><i>R<sub>g</sub></i> &nbsp;from 10 to 50 nm</li><li>Ultra-stable laser</li></ul><p>The microDAWN and its companion<strong> microOptilab™ Refractive Index Detector</strong> interface to most standard UHPLC systems. As these detectors are based on the advanced technology of Wyatt's miniDAWN and <strong>Optilab™</strong>, respectively, users may be confident in the underlying capabilities cited in <strong>thousands of peer-reviewed publications</strong>.</p><h5><strong>Ultrasonic Cleaning Included</strong></h5><p>Each microDAWN includes a <strong>COMET™ ultrasonic transducer</strong> that cleans MALS flow cells automatically by agitating the fluid and loosening particles from the glass surfaces.</p><h4><strong>Specifications</strong></h4><h5><strong>Measurement Capabilities</strong></h5><ul><li><strong>Molar Mass Range:</strong><br>From 200 Da to 10 MDa for proteins; up to 1 MDa for linear polymers<br><i>(Typical, depending on dn/dc, sample concentration, and chromatography conditions)</i></li><li><strong>Molecular or Particle Size (Radius of Gyration, Rg):</strong><br>10 nm to 50 nm, extendable up to 150 nm with shape-specific modeling</li><li><strong>Hydrodynamic Radius (Rh):</strong><ul><li><strong>Flow mode:</strong> 0.5 nm to 30 nm</li><li><strong>Batch mode:</strong> 0.5 nm to 1 µm<br><i>(Requires WyattQELS™ DLS module or DynaPro™ NanoStar™ with fiber optic connection)</i></li></ul></li><li><strong>Sensitivity:</strong><br>Detects as little as 3.5 ng of 100 kDa polystyrene in THF or 70 ng of BSA in PBS, assuming use of a 15 cm UHPLC-SEC column with no post-column filter</li></ul><h5><strong>Optical System and Detectors</strong></h5><ul><li><strong>MALS Detectors:</strong><br>Three high-gain photodiodes with broad dynamic range for multi-angle light scattering</li><li><strong>Dynamic Range:</strong><br>3,300,000:1</li><li><strong>Auxiliary Detectors:</strong><ul><li>Laser monitor for stabilization feedback</li><li>Forward transmission monitor for absorbing samples and data quality assessment</li></ul></li><li><strong>Optional DLS Detection:</strong><ul><li>Integrated WyattQELS™ module within the microDAWN chassis</li><li>External DLS connection via fiber optic from DynaPro™ NanoStar or Mobius™ DLS-ELS instruments</li></ul></li></ul><h5><strong>Laser Specifications</strong></h5><ul><li><strong>Wavelength:</strong><br>658 nm ± 4 nm</li><li><strong>Power Control:</strong><br>Programmable from 10% to 100%</li></ul><h5><strong>Sample Temperature and Flow Characteristics</strong></h5><ul><li><strong>Sample Temperature:</strong> Ambient</li><li><strong>Interdetector Band Broadening:</strong><ul><li>Upstream detector to microDAWN: &lt; 1.5 µL</li><li>Upstream to downstream detector: &lt; 1.6 µL</li></ul></li></ul><h5><strong>Material Compatibility</strong></h5><ul><li><strong>Wetted Materials:</strong><br>316 stainless steel, fused silica, PEEK, PTFE, and MP35N (iron-free alloy)</li></ul><h5><strong>Electronics and Connectivity</strong></h5><ul><li><strong>Analog Inputs:</strong><br>2 differential inputs, 24-bit resolution, ±10 V input range</li><li><strong>Analog Outputs:</strong><br>1 output from a user-selectable measurement channel, ±10 V range</li><li><strong>I/O Ports:</strong><br>Alarm in/out, auto-inject control, Orbit™ valve integration</li><li><strong>Computer Interface:</strong><br>Ethernet</li><li><strong>Data Transmission Rate:</strong><br>Up to 73 Hz</li></ul><h5><strong>User Interface</strong></h5><ul><li><strong>Display:</strong><br>7” (178 mm) high-resolution multi-touch screen for signal monitoring, instrument settings, and diagnostics</li></ul><h5><strong>Instrument Dimensions</strong></h5><ul><li><strong>Size:</strong> 58 cm (L) x 36 cm (W) x 18 cm (H)</li></ul><h4><strong>Other MALS Instruments</strong></h4><ul><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1114"><strong>DAWN™</strong></a> - The most sensitive MALS detector available, anywhere. Incorporates detectors at 18 angles to determine molar masses from 200 Da to 1 GDa and radii from 10 – 500 nm.<ul><li>Standard option: ambient temperature</li><li>Heated/cooled option: -15 °C to +150 °C</li><li>High-temperature option: ambient to +210 °C</li><li>The DAWN offers special options to handle fluorescent samples: fluorescence-blocking filters and an infrared, 785 nm laser.</li></ul></li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1115"><strong>miniDAWN™</strong></a><strong> -</strong> Second only to the DAWN in sensitivity. Incorporates detectors at 3 angles to determine molar masses from 200 Da to 10 MDa and radii from 10 – 50 nm. Ambient only.</li><li><strong>ultraDAWN™</strong> - Measures multi-angle light scattering and reports the results – weight-average molecular weight <i>M<sub>w</sub></i> &nbsp;and rms radius <i>R<sub>g</sub></i> &nbsp;– in real time.</li></ul>

Products from category MALS detectors focused on GPC/SEC distributed by Waters Corporation (Europe) - page 1

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