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

<div><div>Researchers led by <a target="_blank" rel="noopener noreferrer" href="https://kudova.group.uochb.cz/en">Eva Kudová</a> 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 Staphylococcus aureus.</div></div><div>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.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.These findings support the idea that rationally designed steroid-based molecules could act as antibiotic adjuvants, helping existing drugs overcome bacterial resistance.<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"><blockquote><h4>Original Article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.sciencedirect.com/science/article/pii/S0223523426001613?via%3Dihub">Steroidal hormones and neurosteroids - novel therapeutic strategies in bacterial infections: Design, synthesis, and biological evaluation</a></h4>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;Eur. J. Med. Chem., 2026, 308, 118716<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><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote><h4>Abstract</h4>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 Staphylococcus aureus. Structure-activity relationship analysis identified compounds 13 and 16 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 13 significantly downregulated S. aureus 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.<h4>Instrumentation</h4><h5>Structural characterization</h5><ul><li>AVANCE III 400 MHz NMR spectrometer (Bruker)</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=3&amp;search=LTQ+Orbitrap+XL">LTQ Orbitrap XL HRMS</a> (Thermo Fisher Scientific, ESI)</li></ul></div>

Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections

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.<h4>New biomarkers for metformin use</h4>A team led by Tomáš Čajka from the Laboratory of Translational Metabolism at IPHYS analyzed plasma samples from 637 patients with type 2 diabetes treated with metformin and 143 non-diabetic controls using advanced metabolomics and lipidomics. Among 614 detected metabolites, they identified five from the group of N-lactoyl-amino acids (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.<h4>A sensitive “fingerprint” of the drug’s effect</h4>N-Lactoyl-amino acids are formed in cells by combining lactate and amino acids, thus reflecting the metformin-induced changes in cellular energy metabolism. “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,” emphasizes T. Čajka.<h4>Metabolomics in practice and international collaboration</h4>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 Clinical and Experimental Medicine in Prague and the West Coast Metabolomics Center (University of California, Davis) also participated in the study.The results demonstrate that advanced metabolomics approaches developed at IPHYS within the CarDia project can find highly practical applications both in clinical studies and in personalized monitoring of treatment in patients with diabetes.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://ascpt.onlinelibrary.wiley.com/doi/10.1002/cpt.70205">Untargeted Metabolomics Identifies N-Lactoyl-Amino Acids as Dose-Responsive Plasma Biomarkers of Metformin Adherence in Type 2 Diabetes</a></h4>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 HaluzikClin Pharmacol Ther, 119: 1057-1069<a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1002/cpt.70205">https://doi.org/10.1002/cpt.70205</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><h4>Abstract</h4>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.

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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Quantitative analysis of proteins (Bioanalytic) 

In our laboratory, proteomic analyses, including quantitative analysis of proteins, are performed by HPLC-MS or HPLC-MS/MS methods on a ZenoTOF 7600 high-resolution mass spectrometer (SCIEX).

Quantitative analysis of proteins is important in many industries and applications. Proteins include a diverse group of compounds that participate in virtually every biological process. Proteins are building blocks, hormones, transport molecules, cell receptors, cell growth and differentiation factors. Because of this, the analysis of protein interactions is crucial in drug design and production.Proteins are macromolecules - the basis of their structure are polypeptide chains containing from 100 to more than 10000 amino acids (10 - 100 kDa). Proteins are found in simple and complex forms. Complex proteins contain a non-protein component (sugar, lipids, metal ions or dyes) in their structure.In our laboratory, proteomic analyses, including quantitative analysis of proteins, are performed by HPLC-MS or HPLC-MS/MS methods on a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?manufacturerItems=52&amp;search=ZenoTOF+7600">ZenoTOF 7600</a> high-resolution mass spectrometer (SCIEX). We process the obtained results using Sciex OS, Spectronaut, Skyline software.<h4>MS vs MS/MS</h4>Quantitative analysis of intact protein (whole protein in intact form) leads to the concentration (determined from a prepared curve from a standard (with or without matrix) and confirmation of the identification by superimposing (on a mirrored basis) the MS spectrum of the protein determined in the sample to the MS spectrum of the standard. For your needs, we can generate a list of protein-structured compounds (impurities) that were identified in the sample and determine the ratio of their signal area to the signal area of the analyzed protein.The result of proteomic quantitative peptide analysis allows precise and much more sensitive determination of protein concentration. The analysis is based on MS/MS data obtained for peptides obtained by digestion with proteolytic enzymes. The reported result consists of the concentration of the protein under study and confirmation of its presence based on the determined amino acid sequence. For such analyses, it is recommended to add standards internal standards.<blockquote>Our offer:<ul><li>For proteins and peptides with low masses - intact analysis with MS detection;</li><li>Proteins with masses &gt;20kDa require optimization of the digestion method and MS/MS detection. This results in specific signals from the analyzed protein in the mixture/matrix;</li><li>From complex matrices (including serum, cell culture, fungal suspension), sample analysis involves several steps:&nbsp;<ul><li>Sample purification;</li><li>Digestion to obtain unique peptides to distinguish the analyzed proteins from other proteins in the sample;</li><li>Sample preparation requires appropriate method optimization and validation (let's set validation criteria individually);</li></ul></li><li>Reported quantitative result includes confirmation of the presence of the protein in native form or a peptide derived from it (usually confirmation includes at least two peptide sequences);</li><li>Statistical analysis using tools: MarkerView (PCA), GraphPad Prism, Trends, Sciex OS.</li></ul>To optimize and validate the method, it is necessary to provide a standard, in the case of proteins with high masses - it is recommended to add an internal standard.See also:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://labexperts.com.pl/service/identyfikacja-bialek/">Protein identification</a>,</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1296">Analysis and characterization of monoclonal antibodies</a>.</li></ul></blockquote><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Bioanalytic_Quantitative_analysis_of_proteins_1_de494646f2.jpg" alt="Bioanalytic: Quantitative analysis of proteins." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Bioanalytic_Quantitative_analysis_of_proteins_1_de494646f2.jpg 200w," sizes="100vw" width="777" height="606">

Identification of the substance – what is in your sample? (Bioanalytic)

We are able to identify metabolites and products of chemical reactions, contaminants of biological and chemical substances and preparations, and perform profiling of a series of samples to study the kinetics of transformations.

<h4>Substance Identification - Looking for answers to what's in your sample? - we can help you.</h4>Substance identification based on LC-MS/MS techniques can involve single compounds or mixtures of substances. In our analyses, we rely primarily on the knowledge and skills we have acquired after many years of work. For analysis, we use full laboratory facilities for sample preparation and high-resolution mass spectrometry (<a target="_blank" rel="noopener noreferrer" href="https://labexperts.com.pl/o-nas/">equipment</a>).We use different work algorithms depending on the material we are dealing with and the analytical task to be solved. We use DDA (IDA) or DIA (SWATH) methods or targeted approaches (e.g. MRMhr) if we know what to expect. Thus, we are able to identify metabolites and products of chemical reactions, contaminants of biological and chemical substances and preparations, and perform profiling of a series of samples to study the kinetics of transformations.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Bioanalytic_Identification_of_the_substance_what_is_in_your_sample_2_0f425a648b.jpg" alt="Bioanalytic: Identification of the substance – what is in your sample" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Bioanalytic_Identification_of_the_substance_what_is_in_your_sample_2_0f425a648b.jpg 245w," sizes="100vw" width="1881" height="1156"><h4>COST OF SERVICE</h4>We determine the cost of the service individually. The final cost is influenced by many factors related to the nature of the sample itself and the client's expectations. Thus, the price depends, among other things, on the complexity of the sample preparation procedure, the scope and number of analyses, etc.The service includes (depending on individual arrangements):<h5>Development of sample preparation procedure</h5><ul><li>Depending on the matrix and test substances.</li></ul><h5>Development of analytical methods</h5><ul><li>Application of high-resolution LC-MS/MS analyses using DDA (IDA) or DIA (SWATH) experiments and software to support the development of targeted screening methods.</li></ul><h5>Analysis of results includes:</h5><ul><li>finding and identifying the substances of interest, interpreting MS/MS spectra and proposing a structural formula.</li><li>Comparative analysis of sample series, e.g. PCA,</li><li>profiling of analytes in sample series</li></ul><h5>Reporting of results</h5><ul><li>Compile results into easy-to-read reports.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Bioanalytic_Identification_of_the_substance_what_is_in_your_sample_3_c1b8adc1d0.jpg" alt="Bioanalytic: Identification of the substance – what is in your sample" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Bioanalytic_Identification_of_the_substance_what_is_in_your_sample_3_c1b8adc1d0.jpg 245w," sizes="100vw" width="1919" height="1208">

Characteristics of monoclonal antibodies (Bioanalytic)

At LabExperts, proteomic analyses are performed on a ZenoTOF 7600 high-resolution LC-MS/MS system (SCIEX). For MS/MS analyses, we use Collision induced dissociation (CID) and Electron-Activated Dissociation (EAD) fragmentation.

Antibodies are molecules made up of 4 polypeptide chains: two heavy (H - high-chain) linked to each other by a specific type of chemical bond - a disulfide bridge, and two light (L - light-chain) linked by an identical bond to the heavy chains. Monoclonal antibodies (mABs) are used in various forms - as free molecules, in the form of a drug-antibody combination, and in the form of an immunoconjugate, a drug-antibody-biopolymer combination.Their main use is in highly specific targeted therapy for cancer, cardiovascular, autoimmune and nervous system diseases. They are also used in the treatment of osteoporosis, Alzheimer's disease or transplantation. The range of applications of monoclonal antibodies is systematically expanded. The introduction of a new antibody to the market requires complex product characterization, which involves numerous proteomic analyses, which are performed by LC-MS/MS techniques, among others.<h4>LC-MS/MS</h4>The characterization of monoclonal antibodies involves many aspects, including, but not limited to, a suite of analyses related to confirmation of the structure, chain sequence and degree of modification of the antibody. Post-translational modifications (PTMs) are chemical changes that occur after the translation process. These changes generally result in an increase in the immunogenicity of the drug. For this reason, it is essential to monitor modifications as critical quality attributes (CQAs) during both the production and storage of the drug. To ensure monitoring of CQA points, the primary structure of the protein is characterized based on peptide mapping (peptide mapping) analysis. The protein under study is subjected to proteolytic digestion using enzymes such as trypsin, chymotrypsin, Lys-C, Glu-C. As a result of various proteolytic enzymes, a wide range of peptides is obtained. Ultimately, coverage of the entire sequence of the protein under study is obtained.<figure class="image"><img style="aspect-ratio:1536/947;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Bioanalytic_Characteristics_of_monoclonal_antibodies_3_d94fa1623b.jpg" alt="Bioanalytic: Characteristics of monoclonal antibodies." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Bioanalytic_Characteristics_of_monoclonal_antibodies_3_d94fa1623b.jpg 245w," sizes="100vw" width="1536" height="947"></figure>At LabExperts, proteomic analyses are performed on a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?manufacturerItems=52&amp;search=ZenoTOF+7600">ZenoTOF 7600</a> high-resolution LC-MS/MS system (SCIEX). For MS/MS analyses, we use Collision induced dissociation (CID) and Electron-Activated Dissociation (EAD) fragmentation. This provides us with data for unambiguous identification of protein-building amino acids. We process the results using Sciex OS, Skyline and Spectronaut software.<blockquote>We perform:<ul><li>Whole protein analyses - Intact - to determine the exact mass and confirm the theoretical mass;</li><li>N-glycosylation profile determination (based on MS spectrum reconstruction):<ul><li>Glycosylated form;</li><li>Deglycosylated;</li><li>Glycosylated with reduced disulfide bridges;</li><li>Deglycosylated with reduced disulfide bridges.</li></ul></li><li>Peptide maps:<ul><li>Protein digestion with various proteases so that sequence coverage is close to 100%<ul><li>Analysis of PTMs:</li><li>Location of modifications</li></ul></li><li>[%] of modifications compared to the unmodified sequence</li></ul></li><li>TiPOS testing - (technical proof of similarity) - technical confirmation of the similarity of the protein synthesized by the customer (from several LOTs) with the target protein (provided as a template).</li></ul>In order to maintain the highest possible analytical standards, we perform monoclonal antibody analyses under the regime of an internally developed and implemented laboratory quality system based on GLP principles.See also our other proteomics services: <a target="_blank" rel="noopener noreferrer" href="https://labexperts.com.pl/service/identyfikacja-bialek/">Protein identification</a>, <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1294">Protein quantitative analysis</a></blockquote><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Bioanalytic_Characteristics_of_monoclonal_antibodies_2_cb93143fe6.jpg" alt="Bioanalytic: Bioanalytic Characteristics of monoclonal antibodies." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Bioanalytic_Characteristics_of_monoclonal_antibodies_2_cb93143fe6.jpg 245w," sizes="100vw" width="1536" height="908"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Bioanalytic_Characteristics_of_monoclonal_antibodies_1_0e8ab7cdfa.jpg" alt="Bioanalytic: Bioanalytic Characteristics of monoclonal antibodies." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Bioanalytic_Characteristics_of_monoclonal_antibodies_1_0e8ab7cdfa.jpg 245w," sizes="100vw" width="1536" height="858">

Analysis of Anabolic steroids (Bioanalytic)

We offer a highly specific and sensitive qualitative analysis of a wide profile of anabolics by LC-HR-MS/MS technique (detection limits range from 0.01 to 5 ng/ml, depending on the substance).

<h4>Anabolic substances in urine</h4>The effect of anabolic steroids (<a target="_blank" rel="noopener noreferrer" href="https://en.wikipedia.org/wiki/Anabolic_steroid">more information</a>) is to stimulate the growth of muscle mass and sometimes also bone mass by stimulating protein synthesis or altering calcium metabolism. This effect is often used in sports doping. However, anabolic steroids also have many side effects, as they strongly affect the body's overall hormonal balance.Anabolic steroids used by purely recreational athletes are still not banned in most countries, including Poland. Nevertheless, their amateur use during adolescence often results in the inability to continue a professional sports career into adulthood or leads to hormonal imbalances in the body.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Analysis_of_Anabolic_steroids_Bioanalytic_1_46fa2f41ca.jpg" alt="Bioanalytic: Analysis of Anabolic steroids." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Analysis_of_Anabolic_steroids_Bioanalytic_1_46fa2f41ca.jpg 245w," sizes="100vw" width="1200" height="740">If you want to know whether and which anabolic substances are present in the samples of athletes, or you want to exclude doping in this area - use the offer carried out by us together with the company <a target="_blank" rel="noopener noreferrer" href="http://www.lab4tox.pl/">Lab4Tox</a>. We offer a highly specific and sensitive qualitative analysis of a wide profile of anabolics by LC-HR-MS/MS technique (detection limits range from 0.01 to 5 ng/ml, depending on the substance). The use of high-resolution mass spectrometry (HR-MS and HR-MS/MS) in the analysis of anabolic steroids makes it possible to unequivocally confirm or exclude the presence of a given compound. The list of compounds at present includes:<ul><li>Boldenone undecylenate</li><li>Turinabol</li><li>Drostanolone enanthate</li><li>Drostanolone propionate</li><li>Methandienone</li><li>Methenolone acetate</li><li>Methenolone enanthate</li><li>Nandrolone phenylpropionate</li><li>Oxandrolone</li><li>Oxymetholone</li><li>Stanozolol</li><li>5-alpha-DHT</li><li>6-beta-hydroxymethandienone</li><li>19-norandrosterone</li><li>3'-hydroxystanazolol</li><li>4-beta-hydrozystanazolol</li><li>17-alpha-trenbolone</li><li>Testosterone caproate</li><li>Testosterone cypionate</li><li>Testosterone decanoate</li><li>Testosterone enanthate</li><li>Testosterone isocaproate</li><li>Testosterone phenylpropionate</li><li>Testosterone propionate</li><li>Testosterone undecanoate</li><li>Trenbolone acetate</li><li>Testosterone</li><li>Epitestosterone</li></ul>The list of compounds is not complete and will be systematically expanded according to customer needs.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Analysis_of_Anabolic_steroids_Bioanalytic_2_78729119b0.jpg" alt="Bioanalytic: Analysis of Anabolic steroids is carried out by us together with the company Lab4Tox." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Analysis_of_Anabolic_steroids_Bioanalytic_2_78729119b0.jpg 245w," sizes="100vw" width="625" height="100"><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products?category=54&amp;distributorItems=315">Other analytical methods we offer</a>.

Identification of the proteins (Bioanalytic)

We perform proteomic analyses on a state-of-the-art high-resolution ZenoTOF 7600 (SCIEX), in which the Zeno ion trap and EAD (Electron-Activated Dissociation) technology together make a powerful combination.

Protein identification is based on experimental measurement of peptide molecular weights and matching the amino acid sequence of the protein under study with protein sequences deposited in libraries (databases). Two approaches are most commonly used in proteomic studies: top-down and bottom-up. The top-down method involves analyzing full protein sequences. Bottom-up analyses, on the other hand, use digestion of proteins with proteolytic enzymes. The peptides obtained by digestion are analyzed using a mass spectrometer. Each analysis leads to a comparison of experimental data with data obtained by theoretical digestion of proteins described in the database.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Identification_of_the_proteins_Bioanalytic_2_6231b73f0d.jpg" alt="Bioanalytic: Identification of the proteins." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Identification_of_the_proteins_Bioanalytic_2_6231b73f0d.jpg 245w," sizes="100vw" width="1536" height="766"><h4>LC-MS/MS</h4>Tandem mass spectrometers are commonly used to determine protein sequences. They allow ion selection of pseudomolecular peptides and then fragmentation and measurement of the masses of the resulting fragments. Fragmentation using collision induced dissociation(CID ) is an invaluable tool in targeted and untargeted MS/MS analysis of small molecules. It is important to note that in proteomic analysis, data obtained using the aforementioned fragmentation method may leave gaps. For example, spectra obtained by CID fragmentation do not allow unambiguous differentiation of some amino acids: leucine from isoleucine (identical molar masses and CID fragmentation) and lysine from glutamine (very similar masses). For this reason, we perform proteomic analyses on a state-of-the-art high-resolution <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?manufacturerItems=52&amp;search=+ZenoTOF+7600">ZenoTOF 7600</a> (SCIEX), in which the Zeno ion trap and EAD (Electron-Activated Dissociation) technology together make a powerful combination. It enables the creation of unique fragments to differentiate problematic amino acids and increase the sensitivity and specificity of the analysis.<blockquote>We perform analyses of:<ul><li>samples from solution;</li><li>samples from a gel;</li><li>samples from a complex matrix (by prior arrangement);</li><li>samples from lyophilizer;</li><li>samples previously prepared by the client.</li></ul>Qualitative analysis of proteins includes:<ul><li>To confirm the presence of a protein, the sample is subjected to digestion and the result obtained from experimental data is compared with theoretical data;</li><li>Comparison of experimental data on the masses of peptides included in the analyzed protein with the protein sequences described in the database;</li><li>Analysis and identification of the protein mixture;</li><li>Identification of post translational modifications (PTMs) (we use the tools: Skyline, Spectronaut).</li><li>Reporting of the result including, but not limited to, confirmation of the coverage of the protein sequence obtained in the test sample with the theoretical protein and the list of modified peptides, location and % of modifications.</li></ul>Comparative analyses include:<ul><li>Determining the composition of mixtures;</li><li>Comparison and profiling of sample series - protein identification and trend analysis.</li></ul>Our offer also includes:<ul><li>Support in the planning and execution of studies (the scope is determined individually);</li><li>Assistance in the development of extraction methods from complex matrices - biological fluids, plant tissue, animal tissues (the scope is determined individually);</li><li>Statistical analysis using tools: MarkerView (PCA), GraphPad Prism, Trends, Sciex OS;</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1294">Quantitative analysis of proteins</a>;</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1296">Analysis and characterization of monoclonal antibodies</a>.</li></ul></blockquote><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Bioanalytic_Identification_of_the_proteins_Bioanalytic_1_97cf8c94b3.jpg" alt="Bioanalytic: Identification of the proteins." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Bioanalytic_Identification_of_the_proteins_Bioanalytic_1_97cf8c94b3.jpg 117w," sizes="100vw" width="1500" height="2000">

Products from category Laboratory analyses focused on LC/HRMS - page 1

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