Determines the amino acid composition of the peptide and gives a mass-based measure of peptide content.
The peptide is hydrolyzed in strong acid at elevated temperature until it is reduced to free amino acids. Those amino acids are derivatized to make them detectable, then separated by HPLC, with each one eluting at its characteristic time.
The molar amount of every residue is calculated against amino acid standards and normalized to the composition expected from the stated sequence. Two results come out of this: whether the observed ratios match the sequence, and the total mass of amino acids recovered, which yields peptide content independent of any peptide reference standard.
Sample intake instructions, including the quantity required, are sent once we know which assays you want.