Study On ELISA For Detection Of Bacillus Thuringiensis Insecticidal Protein Expressed In Transgenic Plants

Up to date, Study on Bt transgenic plant is developing quickly. So a rapid and accurate method is very necessary for detection of Bt insecticidal protein. Purification of antigen, preparation of specific antibody and enzyme-labelled antibody and ELISA method were studied for detection of Bt insecticidal protein expressed in Bt transgenic plants. The result was as follows:1. Bt insecticidal protein which was of high purity with a molecular weight of 130KD was prepared by using several biochemical techniques.2. specific antibody was acquired by immunizing white rabbits with purified Bt insecticidal protein as antigen. The antibody was conjugated with HRP by the sodium periodate method and enzyme-labelled antibody was obtained.3. sensitivity of three ELISA methods on two different carriers for detection of purified Bt insecticidal protein was compared. The minimal dectectable value on polystyrene cuvettes by direct ELISA and double antibody sandwich ELISA was higher than by indirect ELISA.But The minimal dectectable value on nitrocellulose papers by indirect ELISA washigher than by direct ELISA and double antibody sandwich ELISA.