Radioiodination of rat hepatoma-specific antigens and retention of serological reactivity.
Papain-solubilized tumour-specific antigens from the aminoazo dye-induced rat hepatoma D23 were purified by a combination of lectin affinity and immunoadsorbent column chromatography. Isolated antigens were radio-iodinated using three procedures and analysed for their reaction with specific antibodies in syngeneic immune sera by double-antibody co-precipitation tests and by the rebinding of labelled antigens to specific and non-relevant antibodies immobilized on Sepharose-4B. Soluble hepatoma D23-specific antigens were labile to radiolabelling, and for optimal retention of serological reactivity it was necessary to protect the antigenic determinant by performing the chloramine T method of iodination with antigen bound to the immunoadsorbent followed by elution from the solid phase with 3M NaSCN. Immunoadsorption chromatography indicated that one consequence of radiolabelling hepatoma D23-specific antigen with 125I was a reduction in the affinity of the labelled antigen for its syngeneic specific antibody.
D000818:Animals; D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000276:immunology; D011232:Chemical Precipitation; D002852:Chromatography, Ion Exchange; D000939:Epitopes; D007074:Immunoglobulin G / Q000276:immunology; D007163:Immunosorbent Techniques; D007457:Iodine Radioisotopes; D007553:Isotope Labeling / Q000379:methods*; D008114:Liver Neoplasms, Experimental / Q000276:immunology*; D051381:Rats
D000951:Antigens, Neoplasm; D000939:Epitopes; D007074:Immunoglobulin G; D007457:Iodine Radioisotopes