Abstract: The antigen and antiserum of crystal protein of Bacillus thuringiensis strains
HD-1, 7216 and CT-43 which were solubilized in alkali or trypsin were
prepared. The circular precipitation reaction, double direction single diffusion reacton, and rocket immunoelectrophoresis were used to quantitate those soluble crystal preteins. The minimal detectable value was 0.25Lg/ml by the circular precipitation, the minimal detectable value was 62Lg/ml by double direction-single diffusion, and the minimal detectable value was 15Lg/ml by rocket immunoelect rophoresis.The result of bio-assay was relevant with that of serological methods. However, methods of serological methods were simpler, faster than bioassay. The circular precipitation was the most simple, the most rapid within the several serological methods. It was first success that the circular precipitation and the double direction-single diffusion were used to quantitate soluble crystal protein of B. thuringiensis.