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).

Abstract: Radioimmunossays for the quantitation of serum thymic factor (FTS), a thymic peptide hormone, are disclosed. Each assay employs an antibody specific for FTS, the monoclonal antibody or the antibody from the antiserum of a host animal; synthetic FTS or FTS analogue as the hormone standard; and a radiolabeled FTS analogue as the tracer. Also disclosed is a method of treating serum or other biological fluid prior to assay of FTS to remove interfering substances.

Abstract: Solid phase synthesis of peptides and proteins have been improved by the use of a trifunctional segment, one functional group of which is bound to a solid support, the other two functional groups being available as substrates upon which identical proteins are synthesized.

Abstract: Peptides containing at least four amino acid residues characterized by the presence of an amidino substituted .alpha.-amino acid such as arginine at the carboxyl terminus manifest activity to control smooth muscle contraction, histamine release and vascular permeability.