Use the results of these tests to perform a mass balance calculation (% Target Peptide + % Peptidic Impurities + % Counter ion + % Water = 100%) to ensure that all peptide preparation components have been accounted for.

Net peptide refers to the combined fractions of the target peptide and peptidic impurities (i.e. deletion peptides). Counter ions and water are not considered part of the net peptide content. The amount of the target peptide is calculated by the multiplication of gross weight x net peptide content x HPLC purity.