What a Certificate of Analysis Does Not Prove

A Certificate of Analysis is the single most important document for verifying a research material. But it is just as important to understand what a COA does not establish — overstating what a purity report proves leads to poor experimental decisions.

A COA reports what was tested — nothing more

A typical research-peptide COA reports identity and reported purity for a specific lot. That is valuable, but it is bounded by the tests actually performed. Unless a report explicitly includes them, a standard COA does not establish:

• Sterility or microbial status
• Endotoxin levels
• Total quantity present (purity is a proportion, not a mass — see identity, purity and quantity)
• Stability over time or under specific conditions
• Suitability for any particular research application

"Batch-specific" only when the lot matches

A report is only batch-specific documentation when its lot number matches the material in hand. A generic report reused across lots, or one whose batch identifier is missing or obscured, provides weak traceability. Our note on batch traceability covers chain-of-custody in more depth.

Using a COA responsibly

Treat the COA as evidence of specific measurements on a specific batch, and design experiments accordingly. Where a property matters to your work but is not reported, it has not been established. TagPep documents identity and reported purity for qualifying batches and supplies all materials strictly for laboratory research use only; the purchaser is responsible for determining suitability and lawful use.

For laboratory research use only. Not for human or veterinary use. Not for human consumption. Not for diagnostic or therapeutic use.