title: Development and clinical evaluation of novel radioimmunoassay for the detection of hepatitis B antigen.
abstract: Australia antigen or hepatitis B antigen (HBAg) is intimately associated with acute and chronic forms of serum hepatitis. It appears in the patient long before the onset of acute serum hepatitis. Transfusion of blood containing this antigen frequently leads to hepatitis in the recipient. Due to this, numerous researches have been done to develop a sensitive diagnostic test for detecting the presence of this antigen. To this date, radioimmunoassay has shown better sensitivity and specificity. The test developed at Curtis Laboratories is a human double antibody solid phase radioimmunoassay which is called RIAcT:HBAg. Human HBAb was absorbed on a polyethylene pellet and placed in a glass test tube to prevent radioactive antibody from binding to it. In this procedure, 0.2 ml of patient unknown serum or plasma is placed into the test tube containing the antibody-coated pellet. The vials with the unknown samples and proper controls are incubated in a water bath at 37 degrees C for 2 hours, washed and incubated further with iodinated human antibody for 90 minutes at 37 degrees C. At the end, the tubes are washed again and counted. The level of antigen present is determined by the radioactivity present. The counts of the patient samples that are at least twice the mean counts of the negative controls are considered positive for HBAg. The sensitivity of this test was checked many times by determining the reactivity of various samples from the Bureau of Biologics. The lowest threshold of this RIA procedure has been 1.07 X 10(10) particles per ml.
mesh_terms: D006509:Hepatitis B / Q000175:diagnosis*; D006510:Hepatitis B Antibodies; D006511:Hepatitis B Antigens / Q000032:analysis*; D006801:Humans; D011095:Polyethylenes; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D006510:Hepatitis B Antibodies; D006511:Hepatitis B Antigens; D011095:Polyethylenes