Fig. 1.

DNA and expression analysis. (a) Southern blot analysis of genomic DNA (10 μg per lane) from independent primary maize transformants, digested with HindIII, which cuts the transforming plasmid once. The DNA was hybridized with a probe specific for BtRB; controls gave no detectable hybridization. The designations 2C and 4C are plasmid copy number controls. (b) Immunoassay of transgenic maize plants expressing BtRB fusion protein (lanes 1 and 4). Nontransformed and transgenic cry1Ac plants were used as negative and positive controls, respectively. Lanes 2 and 3 are negative segregants. Protein extracted from leaf samples (100 μg of total protein per lane) were separated by SDS/PAGE (5% acrylamide) and electroblotted onto nitrocellulose. Bt Cry1Ac and the BtRB fusion protein were visualized by enhanced chemiluminescence using anti-Cry1Ab and horseradish peroxidase as primary and secondary Abs, respectively.