Detection of human PAPP-A and proMBP subunits of htPAPP-A by monoclonal antibodies in Western blot. Lane 1: PAPP A antibody [18A10] (GTX10196); Lane 2: PAPP A antibody [3C8] (GTX10194); Lane 3: PAPP A antibody [5H9] (GTX10191); Lane 4: PAPP A antibody [11E4] (GTX14597); Lane 5: PAPP A antibody [10A5] (GTX10193); Lane 6: PAPP A antibody [3C8] (GTX10194); Lanes 1-4: reducing conditions; Lanes 5-6: non-reducing conditions, heterotetrameric complex was detected by PAPP A antibody [10A5] (GTX10193) and PAPP A antibody [3C8] (GTX10194)