A Certificate of Analysis, usually shortened to COA, is one of the most important documents a research lab receives with a peptide batch, and also one of the most frequently skimmed. At a glance it looks like a simple sheet of numbers and signatures. Read carefully, it tells a lab what was tested, how it was tested, who tested it, what the results were and whether the material in the vial is the material described on the label. For Australian research teams, being able to read a COA properly is a basic skill that supports reliable work, clean records and confident answers when an auditor or supervisor asks where a reagent came from. This guide walks through a typical research peptide COA field by field, explains what each section means and highlights the details worth checking before a batch is used.
What a Certificate of Analysis is, and what it is not
A COA is a document that records the results of analytical tests performed on a specific batch of material. It is tied to a batch or lot number, not to a product in general. That distinction matters: a certificate for one batch says nothing definitive about another batch of the same product.
A COA is also not a marketing document. Its job is to report results against specifications, using named methods, in a way that can be checked. When a document leans heavily on adjectives and light on data, it is not doing the job of a COA, regardless of what it is called. Research-use materials should also carry clear labelling that they are for laboratory and research use only. In Australia, the Therapeutic Goods Administration (TGA) regulates therapeutic goods, and research-use-only materials are not approved for therapeutic use, so a COA for a research peptide supports laboratory quality control rather than any clinical claim.
The header: who issued it and for what
The top of most COAs identifies the document itself. Look for the following fields.
Issuing laboratory or company
This shows who performed or reported the analysis. Some certificates are issued by the supplier based on its own testing, while others are issued by, or include results from, an independent third-party laboratory. Independent testing adds a useful layer of separation between the party selling the material and the party verifying it. If the certificate names a third-party lab, note its name and contact details in your records.
Document number and date of issue
A unique document number and an issue date allow the certificate to be referenced and tracked. If a supplier later revises a certificate, the document number or version should change. Keep the version that matches your batch on file.
Product name and description
The product name should match the label on the vial and the item on your invoice. Some certificates include a short description of the material’s form, such as lyophilised powder, along with the quantity per vial.
Batch and sample identification
This section links the certificate to the physical material in your lab, and it is the single most important thing to check.
- Batch or lot number: must match the number printed on the vial label and, where relevant, the packing slip. If it does not, the certificate is not evidence about your material.
- Manufacture date: indicates when the batch was produced.
- Test date: indicates when the analysis was performed. A long gap between production, testing and supply is worth noting.
- Retest or expiry date: some certificates include a date by which the material should be retested or used, assuming correct storage.
When ordering peptides online Australia labs should make it routine to request the certificate for the specific batch being shipped, then compare batch numbers on receipt. This simple step catches mix-ups early and protects the integrity of everything that follows.
Appearance and physical description
Many COAs include a visual inspection result, typically describing the material’s appearance as a white or off-white powder, or similar. The certificate will usually show a specification, such as the expected appearance, and a result stating whether the sample conformed.
This field is basic, but it is useful at receiving. If the material in the vial looks noticeably different from the description on the certificate, for example discoloured, clumped or wet, record what you see, photograph it and contact the supplier before using the material.
Identity testing: is it what the label says?
Identity tests confirm that the material is the intended compound. For research peptides, the most common identity method is mass spectrometry (MS).
How to read the mass spectrometry result
Mass spectrometry measures the mass of molecules in a sample. The certificate usually shows the theoretical (expected) molecular weight of the peptide and the observed molecular weight measured during testing. If the observed value agrees closely with the theoretical value, within the tolerance stated on the certificate, the identity test is reported as conforming.
Look for three things: the theoretical value, the observed value and the stated result. Some certificates also attach the mass spectrum itself, a chart with peaks representing detected masses. You do not need to interpret every peak to benefit from it; the main point is that the dominant signal corresponds to the expected mass.
Purity testing: how much of the sample is the target?
Purity is usually measured by high-performance liquid chromatography, or HPLC. In HPLC, the sample is dissolved and pushed through a column that separates its components. A detector records each component as a peak on a chromatogram as it leaves the column.
How to read the HPLC result
The purity figure is typically calculated from the area of the main peak as a percentage of the total area of all detected peaks. A certificate might show a specification, such as a minimum purity, alongside the measured result. Check that:
- The method is named as HPLC, ideally with basic conditions such as the detection wavelength.
- The specification and the result are both shown.
- The result meets the specification and any internal threshold your lab has set.
- A chromatogram is attached or available on request.
When a chromatogram is provided, look for one dominant peak with only small additional peaks. Large secondary peaks indicate significant other components, which may be worth discussing with the supplier.
Other tests you may see
Depending on the supplier and the material, a COA may include additional tests. Common examples are listed in the table below.
TestWhat it tells you Water contentHow much moisture is present in the lyophilised material Peptide contentThe proportion of the material that is peptide, as distinct from counter-ions and water SolubilityWhether the material dissolves as expected in a stated solvent Residual solventsWhether solvents used in manufacture remain above set limits EndotoxinLevels of bacterial endotoxin, relevant to some laboratory applications Not every certificate will include every test, and absence of a test is not necessarily a problem. What matters is that the tests listed are clearly described, have stated specifications and show results.
Storage conditions and handling notes
Many certificates include recommended storage conditions. For lyophilised research peptides, storage at -20°C is commonly recommended for longer-term keeping. Once a material has been reconstituted in the lab, suppliers commonly recommend refrigeration and use within a limited period. Compare the certificate’s storage statement with the supplier’s published guidance and your lab’s own procedures, and make sure your labels and storage locations reflect it.
Signatures and approval
The bottom of a COA usually includes a signature or approval from the person or function responsible for releasing the results, along with a date. This shows that the results were reviewed rather than simply generated. A certificate without any form of approval should prompt a follow-up question to the supplier.
Red flags to watch for
Most certificates are straightforward, but a few patterns deserve attention:
- No batch number, or a batch number that does not match the vial
- Results without specifications, or specifications without results
- Analytical methods that are not named
- Identical certificates used for different batches
- Missing dates or approval signatures
- Language that reads like advertising rather than a test report
If any of these appear, contact the supplier and ask for clarification before using the material. A supplier with sound processes will usually answer such questions quickly and clearly.
How suppliers present COAs in practice
Suppliers handle documentation in different ways. Some attach a certificate to every order, while others provide them on request or maintain an online library. Peak Haven, an Australian supplier of research peptides and laboratory supplies, says every batch is independently tested by a third-party laboratory using HPLC and/or mass spectrometry, that Certificates of Analysis are available on request and that it keeps a batch documentation library. The company advertises purity of 99% or higher verified by HPLC. Whatever the supplier, the lab’s job is the same: obtain the certificate for the batch, check it field by field and file it with the receiving record.
Building COA review into lab routine
Reading a certificate once is useful; reading every certificate consistently is better. A short COA review step in the lab’s receiving procedure might include confirming the batch number, checking identity and purity results against specifications, noting storage conditions, recording the issuing laboratory and initialling the review. Store the certificate, digitally or on paper, alongside the inventory entry for that batch so anyone in the team can find it quickly.
Final thoughts
A Certificate of Analysis is the bridge between a supplier’s claims and a lab’s records. By reading each field carefully, from the header and batch identification through identity and purity results to storage notes and approvals, Australian research teams can confirm that the material on their bench is what it is meant to be. That habit supports reproducible research, clean audit trails and a clear understanding of every material that enters the laboratory.
