Abstract: A continuous flow peptide synthesizer (10) has reservoirs (12-42) for amino acid derivatives and reservoirs (154-156 and 161-167) for peptide synthesis reagents and solvents. A column (44) has column segments (224, 226, 228) forming stacked interconnected chambers for holding peptide synthesis polymeric resin supports (260). Each of the amino acid derivative reservoirs (12-42) and the reagent and solvent reservoirs (152-154 and 161-167) are connected through a separate controllable valve (46-76, 154-156 or 182-194) to the column (44). A pressurized source (106) of helium or other inert gas is provided for transferring the amino acid derivatives, reagents and solvents to the column (44). The column segments (224) are also used in a vessel (270) for confining the polymeric resin supports (260) in the vessel during cleavage of the peptides from the supports (260).