Understand the source comparison
How to Read KPV COA: Analytical Method Comparison
HPLC Purity Percentage of target peptide vs total peptide content ≥98.0% (research-grade) Quantifies synthesis success and purification effectiveness Single most important metric. Below 95% indicates compromised quality Mass Spectrometry Molecular weight confi
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- HPLC Purity
- Percentage of target peptide vs total peptide content
- ≥98.0% (research-grade)
- Quantifies synthesis success and purification effectiveness
- Single most important metric. Below 95% indicates compromised quality
- Mass Spectrometry
- Molecular weight confirmation
- 341.45 ± 1 Da (theoretical MW)
- Verifies correct amino acid sequence and detects deletion sequences
- Only method that definitively confirms peptide identity. HPLC alone is insufficient
- Amino Acid Analysis
- Molar ratio of each amino acid present
- K:P:V = 1:1:1 (equimolar)
- Detects incorrect amino acid substitutions missed by MS
- Optional for tripeptides but critical for longer sequences where MS resolution drops
- Endotoxin Testing
- Bacterial lipopolysaccharide contamination
- <1.0 EU/mg (for cell culture applications)
- High endotoxin levels trigger immune responses that confound research results
- Required only for in vitro or in vivo applications. Not relevant for chemical assays
- Water Content (Karl Fischer)
- Residual moisture in lyophilised powder
- <5% by weight
- Excess water reduces effective peptide concentration and accelerates degradation
- Often omitted from basic COAs but critical for accurate dosing calculations