Certificates of Analysis for Peptides: What Researchers Need to Know
A Certificate of Analysis (COA) is more than a quality document — it is your primary tool for verifying that a peptide meets the specifications required for your research. Understanding how to read and evaluate a COA is an essential skill for every peptide researcher.
What Is a COA?
A COA is an official document issued by the manufacturer or an independent testing laboratory that reports the results of quality control testing performed on a specific batch of peptide. It provides objective data about the product's identity, purity, and quality.
Key Components of a Peptide COA
Peptide Identity: The peptide name, sequence, molecular formula, and catalog or batch number should be clearly stated and match your order.
Molecular Weight: The theoretical and observed molecular weights should be reported. The observed value (from mass spectrometry) should closely match the theoretical value, confirming correct synthesis.
Purity (HPLC): Reported as a percentage, this indicates the proportion of the desired peptide relative to total peptide content. Research-grade peptides typically specify ≥95% or ≥98% purity.
Appearance: A description of the physical form (usually white to off-white lyophilized powder).
Net Peptide Content: The actual peptide content as a percentage of total weight. This accounts for counter-ions, moisture, and other non-peptide mass, and is critical for accurate concentration calculations.
Red Flags to Watch For
- Missing or vague batch/lot numbers
- No mass spectrometry data to confirm identity
- Purity reported without specifying the analytical method
- No date of analysis or expiration information
- Results that seem too perfect or identical across batches
How Evolve Aminos Supports Transparency
We believe that quality should be verifiable. Our COAs include complete analytical data and are batch-specific, ensuring that the documentation you receive corresponds exactly to the product in your hands.