Antigenic specificity of mouse sera. Two weeks after boosting, mouse sera were collected to analyze their antigenic specificity. TsoAg was probed with sera from mice immunized with PLG-rSAG1 microparticles (lane 1), rSAG1 (Vet L-10) (lane 2), soluble rSAG1 alone (lane 3), PLG (lane 4) or PBS (lane 5). The mouse mAb TG-1 (lane 6) was conducted as a positive control for the native SAG1 in TsoAg. Standard protein markers (lane M) are shown at the left.