An Enzyme-linked Immunosorbent Assay (ELISA) for PBS Z1, a Defective Phage of Bacillus subtilis

The sensitivity, reproducibility and specificity of an enzyme-linked immunosorbent assay (ELISA) for the defective phage PBS Z1 of Bacillus subtilis have been investigated. It was shown that phages in concentrations between 10⁸ and 2.5 x 10¹⁰ particles/ml could be assayed with this method. The coefficient of variation for concentrations between 5 x 10⁸ and 5 x 10⁹ particles/ml was approx. 10%. From some other Bacillus phages tested, only the defective phages resembling PBS Z1 in morphology were detected efficiently with the ELISA for PBS Z1. A comparison is made between ELISA and other assays for PBS Z1.