Free download · Research use only

The 7-point COA checklist

A certificate of analysis only helps if you know what to look for. Here are the seven things we check on every batch, written so you can check them too.

Identity matches what you ordered

The compound name, and where relevant the amino-acid sequence, should match the product exactly. If the sequence is missing, that is a flag.

The lot number matches your vial

The batch or lot on the certificate should be the same one printed on your vial. A generic certificate that is not tied to your specific lot tells you nothing about what you received.

Purity is stated with a method

Look for a purity percentage and the method used to measure it, usually HPLC. A number with no method behind it is marketing, not data.

Mass is confirmed

Mass spectrometry should confirm the molecular weight matches the expected value for the compound. This is how you know the vial contains what the label says.

Endotoxins are screened

For research peptides, the certificate should report a bacterial endotoxin test with a clear pass and limit. Many sellers quietly leave this out.

Sterility or microbial load is reported

A sterility or bioburden result tells you the material was handled cleanly. Its absence is worth questioning.

The lab is named and the test is dated

An independent, named third-party lab and a test date, ideally with a signatory, mean the results can be traced and trusted. An unsigned, undated, unnamed certificate is just a piece of paper.

Want this as a one-page reference?

Drop your email and we will send you the 7-point checklist to keep, plus a note whenever a new batch is released.