title: Comparative study of 125 I- and (3H)acetate-labeled antibodies in detecting iridescent viruses.
abstract: Radioimmunoassays for detecting cell-associated or released virus are described using either (125)I- or [(3)H]acetate-labeled antibodies. In the first assay system, antigen-antibody complexes were separated from free antibody by centrifugation. Sensitivities of 0.1 mug of iridescent virus could be achieved with either (125)I- or [(3)H]acetate-labeled antibody. In the second assay, the antigen was fixed to cover-slip cell cultures, and then reacted with labeled antibody, unbound radioactivity being removed by repeated washing. Nonspecific binding with this method was 0.5 to 1% of the total radioactivity added and sensitivities of 0.1 or 10 mug were achieved with (125)I and [(3)H]acetate, respectively. Immunoglobulins were labeled at the rate of 1 in 300 for (125)I and 1 in 200 with [(3)H]acetate although there was a 400-fold greater isotopic abundance of (125)I relative to (3)H. The possibility of preparing labeled protein of high specific activity using carrier-free [2-(3)H]iodoacetic acid is discussed.
mesh_terms: D000085:Acetates; D000330:Aedes; D000936:Antigen-Antibody Complex; D000956:Antigens, Viral; D001666:Binding Sites, Antibody; D002460:Cell Line; D004267:DNA Viruses / Q000276:immunology / Q000302:isolation & purification*; D007136:Immunoglobulins; D007457:Iodine Radioisotopes; D007461:Iodoacetates; D008722:Methods; D011863:Radioimmunoassay; D014316:Tritium; D014461:Ultracentrifugation
chemical_list: D000085:Acetates; D000936:Antigen-Antibody Complex; D000956:Antigens, Viral; D007136:Immunoglobulins; D007457:Iodine Radioisotopes; D007461:Iodoacetates; D014316:Tritium