What is a Certificate of Analysis?
A Certificate of Analysis (COA) is a formal document issued by a testing laboratory that summarises the analytical test results for a specific batch of a compound. For research peptides, a COA provides documented evidence of the peptide’s identity, purity, and quality, allowing researchers to verify that the material they have received meets the specifications stated by the supplier.
What information does a COA contain?
A comprehensive COA for a research peptide will typically include:
- Compound name and sequence — the full name and amino acid sequence of the peptide
- Batch or lot number — a unique identifier linking the document to a specific production batch
- Molecular formula and molecular weight — the theoretical values for the compound
- HPLC purity result — the measured purity as a percentage, along with the chromatogram
- Mass spectrometry result — the measured molecular weight confirming identity, along with the spectrum
- Appearance — a description of the physical state of the material (e.g. white lyophilised powder)
- Net weight — the quantity of material in the vial
- Testing laboratory details — the name and accreditation of the laboratory that performed the analysis
- Date of analysis — when the testing was performed
Why is a COA important?
For researchers, a COA serves several important functions. It provides independent verification that the material received is what it is claimed to be — not a substitute, mislabelled compound, or degraded sample. It documents the purity level, which is critical for accurate experimental design and interpretation of results. It also provides a traceable record linking the material used in an experiment to a specific batch with documented quality parameters.
Third-party versus in-house COAs
COAs can be generated either by the supplier’s own in-house laboratory or by an independent third-party testing laboratory. Third-party COAs are generally considered more reliable as they are produced by a laboratory with no commercial interest in the result. Independent testing eliminates the potential for bias and provides a higher degree of assurance for the researcher.
How to read an HPLC chromatogram on a COA
The HPLC chromatogram shown on a COA is a graph of detector signal (y-axis) versus time (x-axis). The target peptide appears as the largest peak. Purity is calculated as the percentage of the total peak area represented by the target peak. A high-purity peptide will show a single dominant peak with minimal smaller peaks representing impurities. The retention time of the target peak should be consistent with the expected value for that compound.
Verifying a COA
Some testing laboratories offer online verification tools that allow researchers to confirm the authenticity of a COA using a unique verification code. This provides an additional layer of assurance that the document has not been altered. Janoshik, the independent laboratory used by Trutide, provides a public verification portal at janoshik.com where COA results can be independently confirmed.