Fig. 2.

Purification of RBDr from N. benthamiana leaves agroinfiltrated. a Schematic representation of recombinant antigen purification process. b Stained 12% SDS-PAGE loaded with 10 µg in line 1,2,3,6 ; 200 ng in 4,7 and 1 µg in 5,8. Bottom, Western blot using the anti-histidine monoclonal antibody conjugated with peroxidase of the fractions obtained during purification; 1: TSP extract containing the RBDr; 2: matrix unbound fraction; 3: washing of the process at 70mM of imidazole; 4 and 5: Elution of the RBDr at 500mM; 6: + P19 leaves extract; 7: RBD produced and purified from E.coli; 8: eluate of concentrated RBDr in centricon (3.0 MWCO, Sartorius); MW: Prestained SDS-PAGE standards, Broad Range, cat # 161–0318 (BIO-RAD, USA); simple arrow indicates the band corresponding to the RBDr protein and the double arrow is E. coli his-RBD