title: Immunological and biochemical characteristics of acid citrate eluates from tumour cells: a major non-immunoglobulin component.
abstract: Using competitive double-antibody radioimmunoassays we have shown that immunoglobulin (especially IgA) can be recovered in pH 3.5, 0.12M acid citrate eluates of freshly excised CCH1 tumour-cell suspensions. Studies with 125I-labelled eluates indicate that such preparations exhibit a variable, but appreciable, degree of non-specific binding to unrelated syngeneic tumour and normal tissues. PAGE/SDS gel electrophoresis of the labelled eluates revealed the presence of a major non-immunoglobulin component of 33-36K dalton which could account in part for the non-specific binding observed. This component was also detected in similar eluates from cultured CCH1 tumour and in all other tumour-cell eluates examined to date. In contrast, preliminary data suggest that it is less prevalent in acid citrate eluates from normal tissue, with the exception of peritoneal-exudate cells. The possible origins, nature and significance of this non-immunoglobulin component are discussed.
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000032:analysis*; D002951:Citrates; D004591:Electrophoresis, Polyacrylamide Gel; D005354:Fibrosarcoma / Q000032:analysis / Q000276:immunology*; D007136:Immunoglobulins / Q000032:analysis*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009363:Neoplasm Proteins / Q000032:analysis*; D011961:Receptors, Fc / Q000032:analysis; D012513:Sarcoma, Experimental / Q000032:analysis / Q000276:immunology
chemical_list: D000912:Antibodies, Neoplasm; D002951:Citrates; D007136:Immunoglobulins; D009363:Neoplasm Proteins; D011961:Receptors, Fc