Resources

Proteomics Databases



Metabolomics Databases

• • Edman Sequencing: When N-Terminal Residue Analysis Is Still the Right Choice

  Protein characterization now offers many mass spectrometry-based options for sequence confirmation, peptide mapping, and de novo assembly. In that landscape, Edman sequencing can appear old-fashioned. Yet N-terminal residue analysis by Edman degradation remains a strong choice in many real projects because it answers a focused question with direct chemistry: what amino acids are present at the free N-terminus, in order, starting from cycle one?

• • How Much Does Peptide Sequencing Cost? Factors That Affect Analytical Complexity

  Researchers planning peptide sequencing often ask for a single price before the sample and analytical goal are defined. That question is understandable. Grant budgets, vendor comparisons, and QC timelines all depend on cost predictability. However, this type of analysis is rarely sold as a fixed-price assay.

• • Peptide Sequencing Methods Compared: De Novo Analysis vs Database Search

  Most proteomics workflows use reference-based search as the default route for peptide assignment. The method is efficient, scalable, and well supported when a high-quality reference proteome or expected sequence is available. However, many peptide-level projects do not fit that assumption. A synthetic product may need independent verification.

• • How to Optimize Peptide Sequencing: Sample Preparation, MS/MS Acquisition, and Data Analysis

  Peptide sequence projects often begin with a straightforward need: verify a synthetic peptide, identify an unknown fraction from digestion, or resolve an ambiguous MS/MS spectrum before a larger proteomics decision is made. The expectation is that LC-MS/MS can deliver a dependable amino acid sequence quickly. In practice, weak sequence calls are common.

• • Peptide Sequencing: Principles, Analytical Workflows, and Proteomics Applications

  Peptide sequence is often the first concrete structural answer a proteomics project needs. A synthetic peptide may require verification before downstream use. A fraction from enzymatic digestion may contain an unknown peptide that must be characterized before protein-level conclusions are made.

• • What a Peptide Mapping Service Delivers: From Sample Intake to Coverage Maps and QC-Ready Primary Structure Reports

  Introduction Recombinant protein programs often reach a point where internal teams need primary structure evidence that can support lot release, comparability review, or regulatory documentation.

• • Reading the N-Terminus by Cycles: Edman Sequencing for Protein and Peptide N-Terminal Confirmation

  Introduction Many protein characterization projects do not begin with a full primary structure question. They begin with a narrower but critical one: does the N-terminus match the intended design? A recombinant product may pass intact mass and peptide mapping yet still require direct N-terminal confirmation.

• • Blocked or Weak Edman Signals? Troubleshooting N-Terminal Sequencing Sample Prep and PTM Interference

  Introduction An Edman sequencing run can finish without delivering the N-terminal answer the project needs. The sequencer may complete multiple cycles, yet the first residues are weak, ambiguous, or absent entirely.

• • Monoclonal Antibody Disulfide Bond Characterization and Integrity Analysis

  Monoclonal antibodies (mAbs) are a cornerstone of modern biopharmaceutical development and therapeutic applications. Their structural integrity directly determines drug stability, safety, and biological activity. Disulfide bonds, as critical stabilizing elements of antibody higher-order structure, maintain the three-dimensional conformation and functional properties of antibodies. Accurate characterization of disulfide bond connectivity and integrity is essential for antibody development, manufacturin......

• • Single-Cell iTRAQ Proteomics

  In life science research, understanding the diversity and complexity of cellular functions is fundamental. However, most proteomics studies are conducted on bulk cell populations. Although such approaches provide averaged protein expression profiles, they obscure heterogeneity among individual cells. In recent years, the development of single-cell iTRAQ proteomics has provided a powerful strategy for resolving cellular heterogeneity, enabling the investigation of fine-scale regulatory mechanisms at th......