LABORATORY DOCUMENTATION
How to read a peptide certificate of analysis
A certificate of analysis, or COA, records specified test results for a sample or batch. Read what was measured, the method used and which material the report covers.
Start with the identifiers
Compare the product name, sample identifier, batch or lot number and test date with the material you are reviewing. Check who issued the report and whether the document includes its full pages and referenced attachments. Ask the issuing laboratory about an unclear identifier or verification method.
Separate identity, purity and content
- Identity-related testing: mass spectrometry measures mass-to-charge signals and can support a molecular-weight check. Read the laboratory's conclusion and methods; a molecular-weight match alone does not prove every aspect of structure.
- HPLC purity: chromatographic peak areas describe the relative response of components detected under the stated method. That percentage is not the same as the amount of peptide in the vial.
- Peptide content or assay: this addresses a different measurement. Water, counterions and other material can contribute to gross sample weight, so purity and content should not be treated as interchangeable.
Check the scope of the results
Look for the method, units, measured result and acceptance criterion for each test. A result should be interpreted within the scope of that test. Do not infer unlisted sterility, endotoxin or other results from an HPLC purity percentage.
Request the matching documentation
When contacting BlueLine, include the product name, listed amount and lot or batch number. Ask which reports are available for that material. A report for another batch should not be presented as a result for yours. Documentation here does not establish suitability for human or veterinary use.
Product name · listed amount · lot/batch number · report or test you want clarified
Contact owner for COAs Browse the research catalog →
Further reading
GenScript: interpreting HPLC and mass-spectrometry quality reports
Bachem: identity, purity and peptide-content testing
These references explain analytical methods. They do not certify BlueLine products or imply an affiliation with BlueLine.