Quantitative analysis of NoV GI-1 (A and B) and GII-4 (C and D) recombinant capsid proteins expressed in E. coli by SDS-PAGE and Western blotting. (A and C) SDS-PAGE of recombinant capsid proteins expressed in E. coli with NoV GI-1 (A) and GII-4 (B). Lanes: 1, protein size marker; 2, BSA, 1 μl (4 mg/ml); 3, 0.5 μl each capsid protein; 4, 1 μl each capsid protein; 5, 2 μl each capsid protein; 6, 4 μl each capsid protein. (B and D) Western blot probed with polyclonal antisera produced from this study to each capsid protein. Lanes: 1, protein size marker; 2, recombinant capsid protein.