Species cross-reacting epithelial and urothelial specific antigens in human fetal, adult, and neoplastic bladder epithelium.

Antiserum from a New Zealand White rabbit was raised against the saline-soluble fraction of homogenates of calf urinary bladder epithelium. After absorption, with human red blood cells, human, calf, and mouse sera, and nonepithelial organs, this antiserum was specific for all human epithelia tested. Further absorptions with nonurinary tract epithelia rendered the antiserum specific for urothelium. Species cross-reactivity was seen between the superficial cell layers of calf, human fetal, and adult bladder epithelia. The antigen appeared to be cytoplasmic and was also present (although to a lesser extent) in human bladder tumor biopsy specimens and human bladder tumor cell lines.