(a) Purification of rL7/L12 and rOmp25: SDS-PAGE gel stained with coomassie blue stain showing purification of rL7/L12 and rOmp25 recombinant proteins corresponding to 17 KDa and 25 KDa, respectively. (b) Immunoblotting with polyclonal sera of mice immunized with divalent vaccine (Omp25+L7/L12): The reactivity of purified proteins was confirmed by immunoblotting using anti-Omp25+L7/L12 mice serum. Negative control (lane 1; E. coli BL21 (DE3) cells with pET28a only), marker (lane 2) Precision Plus Protein™ Dual Color Standards, BIORAD #1610374, rOmp25 (lane 3), and rL7/L12 (lane 4). (c) Prediction of virulent proteins in a bacterium using VirulentPred: The sequences for Brucella abortus protein, Omp25 and L7/L12, have been submitted as input and their predicted scores have been calculated using VirulentPred software. (d) Prediction of vaccine antigens using VaxiJen: The sequences for Brucella abortus protein, Omp25 and L7/L12, have been submitted as input and the probability of these proteins being vaccine antigens has been predicted using VaxiJen.