When a laboratory orders synthetic peptides for research, the single most important document accompanying the shipment is the Certificate of Analysis (COA). A COA is a batch-specific test report that connects a physical sample to its claimed identity and purity. Yet many researchers receive peptide COAs without knowing how to evaluate them \u2014 or worse, accept them at face value without verifying the data behind the headline numbers.
This guide explains how to read a peptide COA critically: what the key sections mean, how the numbers are generated, and which red flags signal that a COA may not be worth the paper it is printed on.<\/p>\n\n\n\n