What is a COA?
A Certificate of Analysis (COA) is a lab-issued document that verifies the identity, purity, and quality of a specific production lot. Every BioFirst lot ships with a third-party COA - meaning the testing was performed by an independent laboratory, not the manufacturer. This matters because manufacturer self-testing can introduce bias or conflict of interest.
A proper COA includes at minimum:
- Lot number - unique identifier for the production batch
- Peptide name and sequence - confirms what was synthesized
- HPLC purity data - chromatogram with purity percentage
- Mass spectrometry data - confirms molecular weight/identity
- Residual solvent analysis - ensures safe handling for research
- Endotoxin testing - critical for cell culture work
- Test date and lab name - traceability and accountability
HPLC: the purity fingerprint
High-Performance Liquid Chromatography (HPLC) is the gold standard for peptide purity analysis. The instrument separates compounds in a sample based on their chemical properties, producing a chromatogram - a graph with peaks at specific retention times.
Here is what to look for in the HPLC section of a COA:
The main peak
The chromatogram should show a single dominant peak at a specific retention time. This peak represents the target peptide. The area under the peak (expressed as a percentage) is the purity value. For research-grade peptides, this should be 98% or higher.
Impurity peaks
Smaller peaks at different retention times indicate impurities - typically truncated sequences, deletion sequences, or residual protecting groups from synthesis. These are normal in small amounts but should not exceed 2% combined for a research-grade lot.
Retention time
The retention time should match the reference standard for the specific peptide. A shift in retention time can indicate a wrong sequence or a modified product.
Mass spectrometry: identity confirmation
While HPLC tells you purity, mass spectrometry (MS) tells you identity. The instrument measures the molecular weight of the compound, which must match the theoretical molecular weight of the peptide.
For example, if you order BPC-157 (theoretical MW ~1419.5 Da), the MS data should show a peak at or very near this molecular weight. A significant deviation means you have the wrong compound - even if the HPLC purity is 99%.
Why both tests matter
A peptide can be 99% pure (HPLC) but still be the wrong peptide (MS). HPLC alone confirms purity but not identity. Mass spec alone confirms identity but not purity. You need both to be confident in what is in the vial.
Reading the purity number
| HPLC Purity | Grade | Use case |
|---|---|---|
| 99%+ | Premium research | Cell culture, in-vitro studies, sensitive assays |
| 98-99% | Research grade | Standard lab use, analytical work |
| 95-98% | Crude/technical | Screening, non-critical applications |
| Below 95% | Not research grade | Should not be sold for research use |
Residual solvents and endotoxins
Two additional tests are critical for research quality:
Residual solvents
Peptide synthesis uses organic solvents (DMF, acetonitrile, TFA). The COA should confirm that residual solvents are below safe thresholds. High residual solvent levels can interfere with cell-based assays and compromise research results.
Bacterial endotoxins
Endotoxin testing measures bacterial lipopolysaccharide contamination. This is essential for any peptide that will be used in cell culture or in-vitro biological assays. Endotoxins can trigger immune responses in cell lines and skew experimental data. BioFirst lots are tested to 0.5 EU/mg or below.
What to watch out for
- Missing MS data - purity without identity is incomplete
- Self-tested lots - manufacturer testing without third-party verification is a red flag
- No lot number - without traceability, the COA is meaningless
- Purity below 98% - not research grade
- Outdated COAs - the COA should match the current lot in the vial
How BioFirst handles COAs
Every BioFirst lot ships with a third-party COA that includes HPLC, mass spectrometry, residual solvent, and endotoxin data. We do not rely on manufacturer certificates. If you need a COA for a specific lot before ordering, contact us at info@biofirst.co and we will provide it.