Pepwerk · Access Verification
Pepwerk exclusively distributes research chemicals for use in authorized laboratory environments. Access is restricted to individuals of legal age acting within the scope of a scientific institution.
By accessing, you confirm that all products are purchased exclusively for research purposes · Not for human consumption
Access denied
This shop is accessible exclusively to individuals of legal age acting within the scope of a scientific institution.
Analytics
A CoA purity value of 98% does not mean the same as biological activity. The difference between analytical purity and potency — and what researchers really need to know.
The purity value in the CoA — typically measured by HPLC-UV — indicates what percentage of the measured substance amount is accounted for by the target compound. A value of 98% means: 98% of the total peak area measured via UV detection is attributed to the desired peptide.
This value is a purely analytical statement — it describes the chemical composition of the sample, not its biological efficacy in a research model.
Potency refers to the biological activity of a compound in a specific assay or model system. It is typically expressed as EC₅₀ (half-maximal effective concentration) or IC₅₀ (half-maximal inhibitory concentration).
Potency is assay-specific — the same compound can exhibit different activities in different biological systems. A CoA makes no statement about potency.
Key Statement
Purity = chemical composition. Potency = biological activity in the assay. A CoA measures purity — not potency. Both are relevant for research, but they are distinct parameters.
A peptide with high analytical purity may show low activity in a biological assay — and vice versa. Possible reasons:
A complete CoA with HPLC-UV and mass spectrometry provides two independent pieces of information:
A CoA with a high purity value and mass spectrometry confirmation is the necessary foundation for reproducible research — but no substitute for assay-specific qualification. For research applications dependent on biological activity, dedicated activity assays should be performed.
A purity value of ≥98% via HPLC-UV ensures that the compound has the desired chemical identity and is free from significant synthesis by-products. This is the standard for research-grade peptides — and the basis for all subsequent research work.
Note
This article is for scientific information purposes only. It does not constitute medical advice. All mentioned products are intended exclusively for research purposes in authorized laboratory environments.
Contents