Fractionation of plasma membrane‐associated tumour‐specific antigen from an aminoazo dye‐induced rat hepatoma

Abstract

Abstract Tumour‐specific antigens from an aminoazo dye‐induced rat hepatoma were liberated in a soluble form following limited papain digestion of tumour cell membrane preparations. Fractionation of the soluble extract by DEAE‐cellulose chromatography, gradient centrifugation and preparative electrophoresis yielded a major antigenic fraction, with an approximate molecular weight of 55,000, together with a range of other minor antigenic components of larger molecular weight. All preparations retained the capacity to inhibit the reaction of antibody in tumour‐immune sera with the plasma membrane of viable hepatoma target cells in the indirect immunofluorescence test. It is considered that the defined antigen fractions isolated provide material suitable for analysing the nature of tumour antigen expression in chemical carcinogenesis and for evaluating the involvement of antigen‐antibody interaction in tumour immunity.