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 10(8) and 2.5 X 10(10) particles/ml could be assayed with this method. The coefficient of variation for concentrations between 5 X 10(8) and 5 X 10(9) 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.