FIG. 5.

UV-spectrophotometric and SDS-PAGE analysis of the diafiltration permeate. Symbols: solid circles, A₂₆₀; open circles, A₂₈₀. Permeate from the Amicon 30-kDa-cutoff spiral-wound cartridge during the first diafiltration step was collected, diluted with the diafiltration buffer, and analyzed by UV spectroscopy at 280 and 260 nm. The spectrophotometer was blanked against the diafiltration buffer. Values at 350 and 320 nm were measured to confirm that sample turbidity was negligible. The inset shows a Coomassie blue-stained SDS-PAGE gel of a 10-fold concentrate of the diafiltration permeate collected at the outset of the diafiltration step.