Resources

Proteomics Databases



Metabolomics Databases

• • Absolute vs Relative Protein Quantification

  Compare absolute and relative protein quantification by reporting goal, calibrator needs, study stage, and documentation depth to choose the right MS workflow.

• • Scoping an Absolute Protein Quantification Project: Calibrators, Panel Size, and Validation Deliverables

  Plan absolute protein quantification with clear calibrator design, panel size, matrix strategy, and validation deliverables. Avoid calibration rework and scope mismatches.

• • Absolute Protein Quantification or Relative Quantitation? Matching AQUA, MRM/PRM, and Label-Free Routes to Your Reporting Goal

  Compare absolute protein quantification with AQUA, relative MRM/PRM, and label-free profiling. Match the route to concentration reporting and study stage.

• • Absolute Protein Quantification Not Meeting Spec? Troubleshooting Calibration Curves, Standard Recovery, and Matrix Bias

  Poor calibration fit or biased concentration values in absolute protein quantification? Learn how to troubleshoot AQUA standards, matrix recovery, and assay design.

• • Absolute Protein Quantification by LC-MS/MS: How AQUA Peptides and Calibration Curves Convert Peptide Signal to Concentration

  Learn how absolute protein quantification uses AQUA peptides, calibration curves, and MRM or PRM assays to report protein concentration in defined units.

• • Big Data in Immunopeptidomics: From HLA Binding Prediction to Personalized Immune Mapping

  In the era of precision medicine, understanding what the immune system recognizes and how immune responses are initiated has become a central scientific question in immunotherapy and vaccine design. Immunopeptidomics represents a key analytical approach for addressing this question. It enables the direct capture and identification of peptides presented by HLA molecules using mass spectrometry, thereby delineating a map of immune recognition. In recent years, with advances in big data analytics and the......

• • How to Enrich Low-Abundance Histone Succinylated Peptides?

  In recent years, advances in epigenetics and protein post-translational modification research have made histone modifications an important focus in life science research. In addition to classical acetylation, methylation, and phosphorylation, succinylation has attracted increasing attention as an emerging acylation modification because of its important roles in chromatin architecture and gene expression regulation. However, compared with more abundant modifications, succinylation is typically characte......

• • Advantages and Disadvantages of Non-reduced Peptide Mapping in Disulfide Studies

  In modern proteomics and biopharmaceutical development, protein higher-order structure and disulfide bond connectivity are critical determinants of protein function and stability. Non-reducing peptide mapping is an analytical technique designed to preserve disulfide bond structures. It enables enzymatic digestion and mass spectrometry analysis without disrupting disulfide linkages, thereby directly revealing disulfide bond connectivity and peptide integrity within proteins. This method is widely used ......

• • What Are the Most Common Histone Ubiquitination Sites?

  Histones are core structural components of chromatin, and diverse covalent modifications of lysine residues within histones play critical regulatory roles in gene expression and chromatin dynamics. Histone ubiquitination is an important epigenetic modification in which ubiquitin, a small regulatory protein, is covalently attached to lysine residues in histones, thereby altering nucleosome structure and regulating gene activity. This modification not only plays a central role in transcriptional regulat......

• • Application of High-Resolution Mass Spectrometry in Molecular Weight Identification

  In proteomics and biopharmaceutical research and development, molecular weight determination is a fundamental yet critical analytical step. Accurate molecular weight measurement is essential for recombinant protein expression verification, monoclonal antibody quality control, and structural characterization of unknown proteins. Conventional methods such as SDS-PAGE can provide approximate molecular weight information; however, their limited resolution cannot fully meet the requirements of modern bioan......