Immunoassay for the qualitative screening detection of Bt Cry1Ab/1Ac protein residues.
The Bt Cry1Ab/1Ac ELISA is an immunoassay for the qualitative screening detection of Bt Cry1Ab/1Ac protein residues. The Bacillus thuringiensis (Bt) Cry1Ab/1Ac protein is an insecticidal crystalline protein expressed by the Cry1Ab/1Ac gene in certain strains of genetically modified plants. This test is suitable for the qualitative detection of Bt Cry1Ab/1Ac in MON810, Bt11, Bollgard, Bollgard II, or WideStrike corn and cotton seeds, leaf tissue, surface water, and soil samples (please refer to the appropriate sample preparation or extraction). If necessary, positive samples can be confirmed by PCR or other conventional methods.
The test is a “sandwich” ELISA based on the recognition of Bt Cry1Ab/1Ac by specific antibodies. Controls, prepared samples, and extracts are added to microtiter wells coated with anti-Bt Cry1Ab/1Ac polyclonal antibodies. The Bt Cry1Ab/1Ac in the controls and samples or extracts will be bound to the antibody coated wells. After a 30-minute incubation followed by a washing step, the “sandwich” is completed by the addition of an enzyme-labeled anti-Bt Cry1Ab/1Ac polyclonal antibody. The enzyme-labeled conjugated antibody is washed from the wells after a 30-minute incubation. After a final washing step, the substrate solution is added to produce a color signal. The intensity of the blue color is directly proportional to the concentration of the Bt Cry1Ab/1Ac present in the sample. The color reaction is stopped after 20 minutes and the color is evaluated using an ELISA plate reader. The sample is considered positive when the absorbance value is above the absorbance value of the negative control reagent.