Research Education
PerformanceLabsUK supplies third party tested research reference materials for in vitro laboratory and scientific research use only, not for human or veterinary use.
A Certificate of Analysis (COA) is the document that links a physical vial to a set of laboratory results. Read properly, it tells a researcher what was tested, how it was tested, which batch the result belongs to and whether the report can be traced back to the laboratory that issued it. Read carelessly, it can look reassuring while proving very little. This guide walks through a typical research compound COA section by section, explains what each line actually confirms, and lists the checks worth making before relying on one.
A COA is a report issued after a sample has been analysed. For research peptides and similar compounds it usually covers three questions: is the sample the compound it claims to be (identity), how much of the material is that compound rather than related impurities (purity), and how much material is in the vial (quantity or content). Some reports add contaminant screening, such as heavy metals. A COA describes the specific sample that was tested. Its value depends on how clearly that sample is tied to the batch a researcher actually receives.
| Field | What it tells you | What to check |
|---|---|---|
| Laboratory name and details | Who carried out the analysis | An independent laboratory you can look up, not the seller's own letterhead |
| Report or task number, verification key | The unique reference for this test | That it can be looked up on the laboratory's own website and returns the same result |
| Sample description | What was submitted, as described by the submitter | That the compound name and stated amount match the product |
| Batch or lot number | Which production batch the sample came from | That it matches the batch number on your vial or order documentation |
| Dates received and analysed | When the work was done | That the date is plausible for the batch and not years old |
| Identity (mass spectrometry) | The measured molecular mass of the main component | That the observed mass agrees with the compound's expected mass within the stated tolerance |
| Purity (HPLC) | The proportion of the chromatogram's main peak relative to everything detected | A realistic figure, the method stated, and ideally the chromatogram itself |
| Quantity or content | The measured amount of compound in the vial | That it was measured, and how close it is to the labelled amount |
| Heavy metals (if tested) | Levels of arsenic, cadmium, lead and mercury, usually by ICP-MS | Results reported per element with units and limits |
| Other tests (if requested) | For example endotoxin, residual solvents or microbial counts | Only treat a property as tested if it appears on the report |
| Method statement and sign-off | How the analysis was performed and who approved it | Named methods and an authorising signature or electronic approval |
Identity is usually confirmed by mass spectrometry. The instrument measures the mass of the molecules in the sample, and the report compares the observed mass with the theoretical mass calculated from the compound's sequence or structure. A close match supports the claim that the sample is the stated compound. HPLC alone cannot do this: a chromatogram can show a single clean peak for the wrong molecule. That is why a COA that reports purity without any identity result answers only half the question.
HPLC (high-performance liquid chromatography) separates the components of a sample, and a detector, commonly UV at a wavelength where peptide bonds absorb, records each one as a peak. Purity is normally reported as the area of the main peak as a percentage of the total peak area detected. A result such as 98.4% means that, under those conditions, 98.4% of the detected signal came from the main component. Real analytical results vary from batch to batch. A catalogue where every compound shows an identical, round figure deserves a closer look.
This is the most commonly misread part of a COA. HPLC purity describes the composition of the material that was detected. It does not tell you how many milligrams of compound are in the vial. Lyophilised peptides can also contain counter-ions and residual water that do not appear as impurities in an HPLC purity figure. A vial can therefore show high purity and still contain less compound than its label states. A separate quantity or content measurement is what addresses the amount, which is why it is worth checking whether a COA includes one.
A COA describes the composition of the sample tested at the time it was tested. It does not establish that a material is safe, sterile or suitable for any use outside the laboratory, and sterility or endotoxin levels should not be assumed unless those tests are listed with results. It also cannot account for what happens after testing, such as storage conditions during transit or handling once a vial is opened. For research materials, a COA is evidence of identity and composition, not of anything beyond that.
Every batch supplied by PerformanceLabsUK is third party tested by Janoshik Analytical for identity, purity and heavy metals (arsenic, cadmium, lead and mercury). The batch-specific COA for any order is available on request from support@performancelabsuk.com; include your order number and, where known, the batch number on the vial. Sample Certificates of Analysis will be published in the COA Library as they become available.
You must be 18 or over to enter this site.
WARNING: This website contains age-restricted content.
Join the list for new compound drops, batch COAs, and plain English research notes. Your code arrives straight away.
All products are supplied strictly for in vitro laboratory research use. Not for human or veterinary consumption.
