Specificity of H3-1B monoclonal antibody against SERPINB12. (A) Immunoblot of H3-1B against 6×His-SERPINB2 (B2), GST-tagged recombinant proteins: GST-SERPINB3 (B3), -B4 (B4), -B13 (B13), -B12 (B12), and GST-Serpinb12 (mB12). Note that only SERPINB12 is detected. (B) Parallel immunoblot of monoclonal anti-GST antibody (1:1000 dilution) with the same recombinant serpins (B2, B3, B4, B12, B13, and mB12) showing detection of all GST-tagged proteins (B3, B4, B12, B13, and mB12). (C) Parallel immunoblot of monoclonal anti-His antibody (1 in 100 dilution) with the same recombinant serpins (B2, B3, B4, B12, B13, and mB12) showing detection of only 6×His SERPINB2. (D) Parallel Coomassie SDS-PAGE to show approximately equal amounts of proteins loaded. MW markers for all immunoblots and SDS-PAGE are in KDa.