Immune chromatography: a quantitative radioimmunological assay.
Immune chromatography, a radioimmunological binding assay, employs paper chromatography to separate immune complexes from free antigen and antibodies. During chromatography free antigen and antibodies become distributed throughout the paper, while immune complexes remain near the bottoms of the strips. The chromatographic differences can be made quantitative by using either iodinated antigens or antibodies. Under these conditions nanogram quantities of antigen can be detected or antibodies in sera diluted several 1000-fold. The immune chromatography assay can also be performed as an indirect assay, since the paper strips are cut from nitrocellulose paper. In this case the immune components are absorbed by the paper during chromatography. Antigen is then detected with an iodinated second antibody. The indirect immune chromatography assay is particularly useful for identifying different sera that react with the same antigen. Reaction with the first serum before chromatography reduces the amount of antigen available to the second serum following chromatography. In addition to characterizing the immune chromatography procedure, we discuss the possible applications of chromatography assays for the quantitation of other types of molecular binding interactions.
D000818:Animals; D000936:Antigen-Antibody Complex / Q000032:analysis*; D000937:Antigen-Antibody Reactions; D002854:Chromatography, Paper / Q000295:instrumentation / Q000379:methods*; D006041:Goats; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007074:Immunoglobulin G / Q000032:analysis; D007457:Iodine Radioisotopes; D011817:Rabbits; D011863:Radioimmunoassay / Q000295:instrumentation / Q000379:methods; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000276:immunology
D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007457:Iodine Radioisotopes; D012710:Serum Albumin, Bovine