Documentation
How do you read a Certificate of Analysis?
A Certificate of Analysis (COA) is the laboratory document that records the test results for one specific batch of a research compound. It states what was tested, the methods used, the measured purity, the net peptide content, and the laboratory that produced it. Reading one comes down to matching the batch reference to your vial and checking the reported purity and net peptide content against the stated standard.
What is a Certificate of Analysis?
A Certificate of Analysis is a document issued by an analytical laboratory that reports the test results for a single, identified batch of material. For a research compound it records the methods used, the measured purity, the net peptide content, and a batch or lot reference that ties the paperwork to the physical vial.
Because each COA is tied to one batch, it is evidence about that batch specifically — not a general statement about the compound. The lot number is what connects the certificate to the material in front of you.
What does each section of a COA show?
Most certificates follow the same structure. The fields below appear on a typical research-compound COA, with what each one reports and how to read it.
| Section | What it reports | How to read it |
|---|---|---|
| Compound & batch/lot | The compound tested and a unique batch or lot reference | Confirm the name matches and the lot matches the number printed on your vial |
| Test method | The analytical techniques applied (e.g. HPLC) | Identifies how purity and net content were measured |
| Purity result | The measured purity, usually as a percentage by HPLC | Compare against the stated purity standard (e.g. 99%+) |
| Net peptide content | The peptide mass per vial, reported in milligrams | Compare against the amount stated on the label |
| Laboratory | The lab that performed the analysis | An independent, named lab indicates third-party testing |
| Date of analysis | When the batch was tested | Establishes when the reported results were generated |
How do you interpret the purity result?
Purity on a COA is most often reported as a percentage derived from an HPLC chromatogram — the proportion of the total signal attributable to the target compound. A result of 99% means the target accounts for 99% of the measured material, with the remainder being related impurities.
Read the purity figure against the stated standard rather than in isolation. A certificate that reports the method (HPLC), the percentage, and the standard it is measured against is more informative than a bare number with no method attached.
What is net peptide content on a COA?
Purity tells you how much of the sample is the target compound; net peptide content tells you how much of the vial's dry mass is actually peptide rather than water, counter-ions, and residual salts from the isolated salt form.
Net peptide content is reported in milligrams and read against the amount stated on the label. A certificate that reports purity by HPLC alongside the net peptide content describes both how pure the material is and how much peptide the vial contains.
How do you match a COA to your batch?
Every vial carries a lot number. That number is the link between the physical batch and its certificate: matching the lot on the vial to the lot on the COA confirms the document describes the material you actually hold.
If the lot numbers do not match, the certificate is for a different batch. Requesting the COA that corresponds to your specific lot is the way to confirm the results apply to your material.
Questions
What is a Certificate of Analysis?
It is a laboratory document reporting the test results — purity, net peptide content, and batch reference — for one specific batch of a research compound.
Does a COA apply to every batch of a compound?
No. A COA describes a single identified batch. The lot number ties it to that batch; a different lot has its own certificate.
What does the purity percentage on a COA mean?
It is the proportion of the measured material attributable to the target compound, typically derived from an HPLC chromatogram and compared against a stated purity standard.
How do I get the COA for my batch?
A COA is available on request for any batch. Email support with the compound name and your order or lot number and we will send the matching certificate.
Keep reading