关键词: 苏云金杆菌HD-1, Bt晶体蛋白, 免疫, 抗体, 效价, 免疫球蛋白

Abstract: The Bacillus thuringiensis HD-1 mixture of endospore and crystal protein were treated with Na₂CO₃ solution (50 mmol/L Na₂CO₃, 50 mmol/L EDTA, pH 10) to get the insecticidal protein. The extracted protein was purified by SDS-PAGE preparation electrophoresis. The highly purified protein with molecular weight of 130 kD was used as an antigen. The antigen was emulsified with Freud's complete adjuvant (first injection) or Freud's incomplete adjuvant (second to fourth injection) and injected into New Zealand white rabbits. The first injection was subcutaneous injection on the back of rabbit. The second to fourth booster injections were intramuscular injection on legs. After 10 days of each injection. The rabbits were bled and check the titre using agar gel double diffusion. Two immunizing dosage of antigen (750 μg and 375 μg, each rabbit and time) were tested to assay the effect of antigen dosage on antibody production. After 10 days of the fourth injection, the immunized rabbits were bled thorough heart. The antiserum from blood of immunized rabbit was collected and stored at 4℃ or -20℃. The results show no effect of the tested immunizing dosage on the quality and titre of antibody. The titre of antibody increases with the time of booster injection and reaches 1/120 by using agar gel double diffusing test. Purification of antibodies is conducted by ammonium sulfate precipitation technique and DEAE cellulose chromatographic fractionation. High quality IgG is obtained and used to be labeled by enzyme. The research results provide scientific base.

Key words: Bacillus thuringiensis HD-1, crystal protein, immunizing, antibody, titre, IgG