title: Tumor-associated blocking factors: isolation from sera of tumor-bearing mice.
abstract: An isolation and partial purifications of tumor-associated blocking factors from the sera of tumor-bearing mice is described. Columns for affinity chromatography were prepared by coupling syngeneic tumor-immune antibodies to Sepharose 4B. Passage of serum through such immunoadsorbent columns removed all blocking activity from tumor-bearers' sera; subsequent elution of the absorbent with 3 M NaSCN recovered the activity. The blocking material was further purified on Sephadex G-200. The data provide evidence for the presence of antigen in tumor-associated blocking factors and are compatible with the hypothesis that blocking factors often consist of antigen and antibodies in the form of immune complexes.
mesh_terms: D000327:Adsorption; D000818:Animals; D000951:Antigens, Neoplasm; D002850:Chromatography, Gel; D007106:Immune Sera / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012513:Sarcoma, Experimental / Q000276:immunology*; D013997:Time Factors
chemical_list: D000951:Antigens, Neoplasm; D007106:Immune Sera