Arai, Tadashi (Chiba University, Chiba, Japan), Shyuko Kuroda, and Michio Ito. Possible utility of a fluorescent antibody technique in the serological identification of antagonistic Streptomyces. J. Bacteriol. 83:20–26. 1962.—The indirect fluorescent antibody technique was extended to the serological investigation of antagonistic Streptomyces. Serological relationship was studied among groups of antagonistic Streptomyces that are related in their ability to produce antibiotics or in their morphological and cultural characteristics. It was also demonstrated that spores and sporophores are as satisfactorily stained as shake-cultured vegetative mycelium.