Premium
Radioimmunoassay of Hepatitis B Virus‐Associated (Australia) Antigen Employing 125 I‐Antibody
Author(s) -
Overby L. R.,
Miller J. P.,
Smith I. D.,
Decker R. H.,
Ling C. M.
Publication year - 1973
Publication title -
vox sanguinis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.68
H-Index - 83
eISSN - 1423-0410
pISSN - 0042-9007
DOI - 10.1111/j.1423-0410.1973.tb03523.x
Subject(s) - radioimmunoassay , antigen , complement fixation test , antibody , titer , antiserum , immunoradiometric assay , hepatitis b , hepatitis b virus , microbiology and biotechnology , immunology , chemistry , virology , virus , biology , medicine , serology
. 125 I‐labeIed specific immune globulin was used in a 2‐step procedure to detect hepatitis B virus‐associated antigen in blood serum or plasma. In step 1, undiluted sample was incubated overnight in polypropylene tubes coated with hyperimmune guinea pig antiserum. The serum sample was then removed and specific 125 I‐antibody was added and incubated for a period of 90 min. The presence of antigen in the original sample was then reflected by the count rate of the tube after the unreacted labeled antibody was removed. A typical dose response curve was observed for antigen in the concentration ranges of 0.005–0.32 μg/ml. Replicate analyses of normal sera and a low‐titer positive sera revealed method variations which were distributed between ± 5 standard deviations from the replicate mean values. The radioimmunoassay was 500–1,000 times as sensitive as complement fixation for ad‐subtype antigens. For ay‐subtype antigens, the method was 128–512 times as sensitive as complement fixation. Assay values of 4,500 blood donor sera had a typical distribution, with most counts falling between +3 and –3 standard deviations relative to a negative control serum. However, 6% of the samples gave a count rate greater than 3 standard deviations from the negative control mean, and about 3.5% gave a count rate greater than 5 standard deviations above the negative control mean. The increased sensitivity of the method resulted in the detection of more positive sera in a variety of donor groups than other immunological methods. In two volunteer donor groups, 1.4 and 1.9% of the samples were positive. In two analyses of commercial paid donors, one group was 4.6% positive and one was 5.5% positive.