Fig. 4

Coomassie blue stained 12% acrylamide gel electrophoresis of the IBs obtained at the end of E. coli BL21 (DE3) cultures producers of RBD-P and RBD. IBs from cultures in shake flasks (A); lane 1: molecular weight marker (MWM), lane 2: IBs of RBD-P, and lane 3: IBs of RBD. IBs from two independent bioreactor cultures (B); lanes 1 and 4 are IBs from cultures producers of RBD-P, lane 3 is the MWM, and lanes 2 and 5 are IBs from cultures producers of RBD. Immunodetection by Western Blot of purified RBD-P and RBD (C) recombinantly produced in E. coli BL21 (DE3) in bioreactor and detected with anti-Spike antibody (Sino Biological 40,591-MM43); lane 1: RBD-P, and lane 2: RBD, and lanes 3 and 4: molecular weight marker (MWM)