What is a certificate of analysis?
For research use only. Not for human or animal consumption.
A certificate of analysis, usually shortened to COA, is a document that reports what a laboratory measured on one specific batch of material. It names the batch, lists the tests that were run, states the method and the acceptance limit for each test, and gives the measured value. Someone at the lab signs or approves it.
That is the whole idea. A COA is not a description of a product in general. It is a record of one lot, on one date, tested one way.
Where COAs come from
COAs started as an ordinary part of quality control in chemical and reagent supply. A manufacturer makes a batch, pulls a sample, tests it against a specification, and releases the batch with a certificate showing it met that specification. The buyer's own QC group files the certificate and, in many labs, checks some of it again on receipt.
Research peptides follow the same pattern. A batch is synthesized, purified and freeze-dried, then a sample goes to a lab for analysis, and the report becomes the COA for that lot.
What a typical COA contains
Layouts differ from lab to lab, but most reports carry the same blocks:
- Header. The issuing lab's name, address and contact details, plus a report or task number.
- Sample information. Product name, lot or batch code, the stated amount per vial, the date the sample was received and the date it was analyzed.
- Test table. One row per test: the test name, the method, the specification (the limit the batch had to meet) and the measured value. Many reports add a pass or fail column.
- Raw data. For chromatography, the chromatogram and its peak table. For mass spectrometry, the spectrum with the observed mass.
- Approval. An analyst signature, initials or an electronic approval line, and sometimes a second reviewer.
COA, specification and SDS: three different documents
These three get confused more than any other paperwork in a lab.
| Document | What it covers | Changes per lot? |
|---|---|---|
| Specification | The limits a product is supposed to meet, such as "purity 98% or higher" | No |
| Certificate of analysis | What one lot actually measured against those limits | Yes |
| Safety data sheet (SDS) | Hazards, handling, spill and disposal information for the substance | No |
A listing that prints "98%+" is quoting a specification. The COA is where a figure like 99.17% for lot 0412 shows up.
Who issues the COA
Some COAs come from the manufacturer's in-house lab. Others come from an independent lab that the supplier sends samples to. Both are real COAs. Where they differ is on the separate question of independence.
What a COA does not show
A COA covers only the tests printed on it. If endotoxin is not on the report, the report says nothing about endotoxin. It also describes the sample the lab received. Whether that sample came from the same lot as a given vial is a separate check, done by matching lot codes.
FAQ
Is a COA the same as a lab test?
A COA is the report of one or more lab tests on a batch. The tests are the work; the COA is the record of it.
Does every batch need its own COA?
For traceability, yes. A report from one lot does not describe another lot, even from the same supplier and the same route.
Can a COA expire?
The document itself does not expire, but it describes the batch at the time of testing. Some suppliers also print a retest date for the material.
Research use only
Peptira supplies materials for laboratory research. For research use only. Not for human or animal consumption. Not for diagnostic or therapeutic use. This page explains a lab document. It is not medical advice and gives no handling or use instructions.