Introduction: “Suitable for Mass Spectrometry”

“Suitable for Mass Spectrometry” (also referred to as MS-grade ) refers to reagents—especially enzymes and chemicals—that meet strict purity and performance criteria for mass spectrometry (MS)-based applications. These reagents are optimized to ensure minimal background noise, high digestion efficiency, and compatibility with downstream LC-MS/MS workflows.

Key Characteristics

1. High Purity and Low Contaminants

· Free from keratin, autolysis fragments, nucleases, proteases, salts, or other interfering substances.

· Avoidance of reagents that produce signal suppression or non-specific signals in MS analysis.

2. Consistent Performance

· Validated for reproducible enzymatic activity and cleavage specificity.

· Batch-to-batch consistency is critical for quantitative proteomics and sequencing.

3. Stability and Formulation

· Supplied in stabilized lyophilized forms or glycerol-free liquid to be compatible with LC-MS workflows.

· Formulated without additives (e.g., Tris, EDTA, glycerol) that interfere with MS detection.

Common MS-Grade Proteases

These enzymes are often referred to collectively as “MS-Grade Proteases” in Chinese when talking about their application in MS workflows.

Typical Applications

1. Proteomics

· Comprehensive analysis of protein expression, modifications, and interactions.

· Label-free or label-based quantification (e.g., TMT, iTRAQ).

2. Protein and Antibody Sequencing

· High-resolution mapping of peptides for de novo or database-driven sequencing.

· Fragmentation mapping of monoclonal antibodies (mAbs).

3. Biopharmaceutical Characterization

· Analysis of biosimilars, therapeutic antibodies, or ADC conjugation sites.

· Post-translational modification (PTM) analysis (e.g., glycosylation, phosphorylation).

4. Biomarker Discovery

· Detecting low-abundance biomarkers in clinical or research settings.

Summary Table ( Chinese version )

Selection Tips

· Check vendor certification: Look for terms like "MS-grade," "mass spectrometry validated," or "sequencing-grade."

· Review digestion performance: Validate enzyme efficiency with known proteins before scaling.

· Avoid stabilizers unless clearly MS-compatible.

Sample LC-MS Workflow with Enzymatic Digestion and Cleanup

This is a practical step-by-step protocol for preparing proteins for LC-MS/MS analysis using MS-grade proteases like Trypsin, Lys-C, or Glu-C.

1. Sample Preparation

2. Enzymatic Digestion

3. Peptide Cleanup

To remove salts, detergents, or inhibitors before LC-MS:

Method Options:

· C18 Reverse-Phase SPE (Solid Phase Extraction) – e.g., Sep-Pak or OMIX tips

· StageTips – home-packed tips with C18 for small samples

· Magnetic Bead Cleanup – e.g., SP3 method (paramagnetic beads)

Ensure final elution is in LC-MS compatible solvents (e.g., 0.1% FA in water or ACN).

4. LC-MS/MS Analysis

View all Suitable for Mass Spectrometry products