How to Verify Peptide Quality: Testing, Purity, COAs and Supplier Transparency

Researchers interested in peptide purity testing should therefore look for more than the final percentage.

Supporting chromatographic information can help explain how that figure was obtained.

Peptide Purity Is Not the Same as Peptide Content

This distinction is particularly important when researchers evaluate peptide quality.

HPLC purity describes the relative purity of detected chromatographic material.

Net peptide content describes something different. It relates to the amount of actual peptide compared with the total material present in the sample.

The total material may also include:

This means a sample can have high chromatographic purity while the percentage of actual peptide relative to total sample weight is different.

Researchers comparing peptides purity information should therefore understand exactly which analytical metric is being presented.

A more complete explanation is available in the Southwest Biologix guide on how to read a peptide COA.