We present two monoclonal antibodies (mab), Mano 4/4 and 486 P3/12, directed against tumor-associated antigens of different subpopulations of transitional cell bladder carcinoma tumors. A detailed description is given concerning their reactivity patterns in an ELISA assay against different cell lines. Using immunohistochemical staining against normal bladder mucosa, mab Mano 4/4 reacts with distinct cells in the basal layer and mab 486 P 3/12 recognizes single cells in the superficial layer. Analysing different transitional-cell carcinomas, mab Mano 4/4 reacts with 17 of 20 and mab 486 P 3/12 with 17 of 19 bladder tumors. It is emphasized that both mabs may add new information in respect to a better characterization of the heterogeneity of bladder carcinoma. A biochemical characterization of the mabs and their corresponding antigens is given. Mab Mano 4/4 is directed against a 28 kD glycoprotein and mab 486 P 3/12 is reacting with a 200 kD glycoprotein belonging to the family of CEA-like proteins.
