How to verify a peptide Certificate of Analysis (COA)
Verifying a COA means confirming it with the laboratory that issued it. This guide covers how to do that, what to compare and what to check on the report itself.
What does it mean to verify a COA?
To verify a COA is to confirm, with the laboratory that issued the report, that the laboratory has the same report. The report you hold is one copy; the laboratory's own record is a second source to compare it with. A confirmed report is still only a record of what the laboratory measured in its own sample.
How do you check a COA with the laboratory?
You check a COA with the laboratory through the laboratory's own lookup page or its contact details. Use the identifier or the client name printed on the report. The laboratory is named in the report's header, and the identifier is a search code or a certificate ID.
How to read a peptide COA shows where each of these sits on the report.
What should you compare between the laboratory's copy and yours?
Compare every item in the table below. Each one has a place on the report and a meaning when the two copies agree.
| What to compare | Where it is on the report | What agreement tells you |
|---|---|---|
| Client | The header. | The laboratory did the work for the party named on both copies. |
| Sample or compound name | The header. | Both copies describe the same sample. |
| Lot field | The header. | Both copies give the same lot. |
| Dates | The header: received, tested and reported. | Both copies carry the same dates. |
| Reference | The header, as a search code or certificate ID. | The laboratory finds the report under the reference you hold. |
| Results | The purity, identity and net content sections, with the chromatogram and spectrum. | Every result and every image reads the same on both copies. |
If an item differs between the two copies, note which item and contact the laboratory.
What can you check on the report itself?
Four checks need only the report, and none replaces confirming it with the laboratory.
Client line. The client line names the party the laboratory did the work for. Compare it with the party you expect.
Dates in order. The received date is not later than the reported date, and neither is in the future.
Labelled ions. The mass spectrum labels each ion by its mass-to-charge ratio. A peer-reviewed review notes that multiple-protonation of proteins and peptides occurs in the ESI process, so a labelled value reflects the compound's mass plus the added protons, divided by the number of charges. The same review says the molecular weight can be calculated from two adjacent ions. Worked back, each labelled ion should give the mass calculated for the compound.
Peak areas. If the report lists peak areas, divide the main peak's area by the total of all peak areas. Bachem says the area of the main peak in relation to the total area of all peaks reflects the peptide purity, so the result should agree with the purity the report states.
What does it mean if the laboratory cannot find the report?
If the laboratory cannot find a report, that report cannot be confirmed with that laboratory. That is all it means.
How Excalibur Peptides reports are checked
Anyone can open Excalibur Peptides reports on Freedom Diagnostics Testing's lookup page, with no account: search the company name, Excalibur Peptides. The results list an Open PDF link for each report. The QR code on each vial label opens the laboratory's site.
If you hold a report, you can enter its search code instead. It is in the Search Code field in the table at the top right of the report. The laboratory says codes are not case-sensitive and that spaces should be removed. The COA page explains what each report shows.
What are the steps, in order?
Verify a COA in six steps.
- Read the laboratory's name, the client line and the reference on the report.
- Open the laboratory's own lookup page, or use its contact details.
- Search with the reference or the client name printed on the report.
- Compare the laboratory's copy with yours: client, sample, lot, dates and results.
- Run the checks on the report itself: client line, dates, labelled ions and peak areas.
- If the laboratory cannot find the report, record that it could not be confirmed with that laboratory.
How to read a peptide COA explains each part of the report these steps use.
For research purposes only. Not for human consumption.
Last updated
