Abstract: A unique monoclonal antibody against P-glycoprotein. The monoclonal antibody is different than those previously described and has the surprising property of reacting to a soluble form of P-glycoprotein. The invention further includes a novel hybridoma cell line which produces the antibody. A preferred embodiment of the novel antibody has been designated F4 which is believed to react at or near an extracellular transmembrane loop of P-glycoprotein selected from the group consisting of the third and sixth extracellular loops. The invention further comprises a method for detecting the presence of P-glycoprotein comprising reacting a specimen containing P-glycoprotein with the novel monoclonal antibody and detecting the reaction to show that P-glycoprotein is present.

Abstract: Monoclonal antibodies to adenocarcinoma cells, and, in particular, breast carcinoma cells, are produced by a hybridoma formed by fusing mouse lymphocytes and mouse myeloma cells. The monoclonal antibodies are capable of shrinking solid tumors associated with human breast. The monoclonal antibodies identify an antigen associated with carcinomas of ductal lineage. The monoclonal antibodies, specifically, F36/22 monoclonal antibodies, can be used diagnostically and therapeutically.

Abstract: A prostate antigen distinct from prostatic acid phosphatase has been detected in normal, benign hypertrophic and malignant prostatic tissues, but not in other human tissues. The prostate antigen was purified to homogeneity from prostatic tissues by ammonium sulfate precipitation, DEAE-BioGel A anion exchange chromatography, molecular sievings on Sephadex G-100 and Sephadex G-75, and preparative polyacrylamide gel electrophoresis. The purified prostate antigen shows a single protein band on analytical polyacrylamide gel electrophoresis and isoelectric focusing. The molecular weight of purified antigen was estimated by Sephadex G-75 gel filtration to be 33,000 and by sodium dodecyl sulfate polyacrylamide gel electrophoresis to be 34,000 with no subunit. The prostate antigen had an isoelectric point of 6.9.

Abstract: A prostate antigen distinct from prostatic acid phosphatase has been detected in normal, benign hypertrophic and malignant prostatic tissues, but not in other human tissues. The prostate antigen was purified to homogeneity from prostatic tissues by ammonium sulfate precipitation, DEAE-BioGel A anion exchange chromatography, molecular sievings on Sephadex G-100 and Sephadex G-75,This invention was supported in part by Grants No. CA-15126 and CA-15437 from the National Cancer Institute, U.S. Public Health Service.