Panel a, a panel of six purified monoclonal antibodies react with the antigen Trx-boPAG1 which was used for immunization. Panel b, the same six mAbs were tested for reactivity against an irrelevant Trx-containing antigen. The mAb 3D9 reacts with the antigen used for immunization (Panel a) but not with the irrelevant antigen (Panel b).