Quality Standards: Certificates and Traceability
Guide on quality standards for research peptides. COA, purity testing, sterility and good manufacturing practices.
Equipment required
Certificat d'analyse (COA) Documentation lot
Importance of Quality
In peptide research, material quality determines the reproducibility of results. A poor-quality peptide may contain impurities that distort experimental data.
Certificate of Analysis (COA)
Essential Elements
- Product identity: Name, lot number, sequence
- HPLC purity: Percentage and chromatogram
- MS confirmation: Measured vs theoretical mass
- Peptide content: % active peptide (vs salts/water)
- Appearance: Visual description (white powder, etc.)
Acceptance Criteria
| Parameter | Specification | Method |
|---|---|---|
| Purity | ≥ 98% | HPLC-UV |
| Identity | M ± 0.1% | ESI-MS or MALDI |
| Peptide content | ≥ 80% | AAA or gravimetry |
| Endotoxins | < 1 EU/mg | LAL (if applicable) |
Analytical Tests
HPLC (Chromatography)
Separates compounds by chemical affinity. Allows quantification of purity and detection of impurities.
Mass Spectrometry
Confirms identity by precise molecular mass measurement. Detects unexpected modifications.
Amino Acid Analysis (AAA)
Complete hydrolysis then quantification. Verifies composition and determines actual peptide content.
Traceability
Lot Number
Each lot must have a unique identifier enabling traceability of:
- Synthesis date
- Raw materials used
- Operators involved
- QC test results
Documentation
Retain COAs for at least 5 years. Raw data (chromatograms, spectra) must be archived.
Quality Red Flags
- No COA or generic COA
- Unverifiable purity (no chromatogram)
- Measured mass very different from theoretical
- Abnormal appearance (coloration, moisture)
- Abnormally low price
Best Practices
- Always request COA before purchase
- Verify data consistency
- Keep reference samples
- Document any observed deviation