Amino acid chromatographic profile (aminogram) of Transferon. Comparison between standard mixture of hydrolyzed proteinogenic amino acids (Waters™) (red line) and batch 15A02 of Transferon (blue line). A sample matrix derivatization control is also shown (black line). A total of 17 of the 20 known proteinogenic amino acids were detected using the amino acid standard. The amino acid chromatographic profile also showed three unidentified peaks, which were labeled as U1 (2.25 min), U2 (2.37 min), and U3 (6.80 min). Figure S2 evinces the notion that the aminogram profile is consistent between the 10 Transferon batches. The samples were analyzed using an Acquity C18 column (1.7 µm, 2.1 × 100 mm) with a mixture of acetonitrile-formic acid-water as the mobile phase using a gradient configuration. The column was maintained at 43°C, and UV detection was monitored at 260 nm. AMQ, NH3, and deriv. peaks originate from the reaction of derivatization. AU: area units.