Western blot analysis of dual antigen plague vaccine construct, RCN-F1/V307, versus individual constructs, RCN-F1 and RCN-V307. Vero cell monolayers were infected with RCN constructs at an MOI of 1 and pellet (pt) and supernatant (sup) fractions were harvested 24 h post infection. Blot A was probed with anti-V antibody, and blot B was probed with anti-F1 antibody. Arrows indicate Vt and F1 proteins. Lanes for blot A are: (1) ladder, (2) RCN-V307 pt, (3) RCN-V307 sup, (4) RCN-F1/V307 pt, (5) RCN-F1/V307 sup, (6) RCN-F1 pt, (7) RCN-F1 sup. Lanes for Blot B are: (1) ladder, (2) RCN-F1 pt, (3) RCN-F1 sup, (4) RCN-F1/V307 pt, (5) RCN-F1/V307 sup, (6) RCN-V307 pt, (7) RCN-V307 sup.