Crystal proteins (Cry) from Bacillus thuringiensis (Bt) are well-known pesticidal proteins in genetically modified (GM) crops and often used as the target proteins in detection of GM food. Instead of the classic mouse hybridoma, new rabbit monoclonal antibodies (McAb) were first produced in detection of GM food. Rabbit McAb and polyclonal antibodies (PcAb) were prepared using Bt-Cry1Ac protein as the immune antigen (Ag). Sandwich ELISA with either PcAb as the coating antibody and peroxidase horseradish (HRP) labeled McAb as the detecting antibody (PcAb-Ag-McAb), or McAb as the coating antibody and HRP labeled PcAb as the detecting antibody (McAb-Ag-PcAb), was developed for detecting Bt-Cry1Ac protein. The analytical sensitivity of McAb-Ag-PcAb was higher with the linear detection range of 0.97-62.50 ng mL-1 and the limit of detection (LOD) of 0.24 ng mL-1. There was no cross-reaction with Cry1Ab and Cry1c proteins and the mean recovery was 103.35% in corn leaves. The LOD and the linear detection range of the proposed ELISA are more satisfactory than other ELISA systems using an anti-Cry1Ac PcAb or two Cry1Ac-specific McAb for detection of the target protein and the research provides an effective instrument for detecting Cry1Ac protein in GM crops and their derivatives.

Yu-Rong Zhou, Chao-Nan He, Geng Ni, Xiaodong Zheng, Wen-Wen Zhou. A novel sandwich ELISA system using rabbit monoclonal and polyclonal antibodies for rapid detection of Bt-Cry1Ac protein. International Journal of New Developments in Engineering and Society (2019) Vol.3, Issue 3: 25-39. https://doi.org/10.25236/IJNDES.19303.

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