In this Application Update, we combine into a single method individual improvements made to the standard AAA-Direct gradient program. These individual improvements are now in the AAA-Direct manual. This update shows that such combined changes to the AAA-Direct method improve the performance of our previously published method. This new method successfully determines amino acids in yeast extract-peptone-dextrose yeast culture medium (YPD Broth), and Dulbecco’s modified Eagle’s (with F-12), M199, L-15 (Leibovitz), and McCoy’s 5A media for mammalian cell culture.
This application note shows that AAA-Direct can be used to determine peptides with lysine hydroxylation. All common amino acids, including hydroxylysine (Hyl), were separated by AAA-Direct, and the presence or absence of Hyl in the fractions confirmed peak identities. The techniques described in this application note show several ways that peptides can be evaluated for identity and purity, how peptides can be desalted, and how much desalting is needed for successful AAADirect amino acid analysis.
