Understanding COA Basics
A Certificate of Analysis (COA) is your primary tool for verifying peptide quality. This document provides laboratory test results showing purity, composition, and contamination levels. Every reputable vendor should provide COAs for their peptides.
Key Sections to Review
Purity Analysis: Look for HPLC (High Performance Liquid Chromatography) results showing percentage purity. Research-grade peptides should typically show 95% or higher purity. The chromatogram should display a single dominant peak.
Mass Spectrometry Results: This confirms the peptide's molecular weight matches the expected value. Look for peaks at the correct mass-to-charge ratio (m/z). Multiple peaks or significant deviations indicate impurities or degradation.
Water Content: Karl Fischer titration results show moisture levels. High water content can indicate poor storage or handling. Acceptable levels vary by peptide but generally should be under 10%.
Endotoxin Testing: Bacterial endotoxin levels should be reported, especially for injectable peptides. Look for LAL (Limulus Amebocyte Lysate) test results showing levels below 5 EU/mg.
Red Flags to Avoid
Be cautious of COAs with missing test dates, no batch numbers, generic results that seem identical across different peptides, or results that are too perfect (exactly 100% purity is suspicious).
Disclaimer: This information is for research purposes only and not medical advice. Always verify peptide quality through proper analytical methods before use in research applications.