Color-monitored solid-phase multiple peptide synthesis under low-pressure continuous-flow conditions.

Exemplified on fifty peptides derived from proteins of the human immunodeficiency virus (HIV), we summarize our experiences with rapid solid-phase multiple peptide synthesis under low-pressure continuous-flow conditions on standard polystyrene-based resin in a series of concatenated flow reactors with adjustable volume. Alternatively, multiple batchwise synthesis in plastic syringes may be used as a still simpler but a more elaborate procedure. Completeness of acylation of resin-bound free amino groups was monitored by the acid-base indicator bromophenol blue. Efficiency of the coupling reaction was increased by exposure to elevated temperature in an ultrasonic bath. Up to 100 mg of crude peptides were purified on a mass-overloaded Vydac C18 reversed-phase semipreparative HPLC column in one run, this procedure ensuring high recovery of homogeneous peptides. The peptides synthesized were serologically relevant to the detection of anti-HIV-1 antibodies in positive sera.