HBs Ag Confirmation
In the screening of blood units for Hepatitis B surface Antigen or HBsAg some false positivity may happen, leading to a misinterpretation of the assay results and a misclassification of the blood unit and the donor. To confirm the positivity of a screened sample or to confirm the presence of an ongoing HBV infection in a hospitalized patient, a confirmatory test has to be run.
The device has to be used in combination with the product code SAG1.CE for the determination of HBsAg in human sera and plasma.
The sample, whose repeatedly positivity for HBsAg has to be confirmed, is premixed with a reagent containing high titer anti HBsAg antibodies that will neutralize the antigen is really present in the sample.
The neutralized sample is then tested for HBsAg according to the procedure reported for the specific device. If the positivity in the first screening test is specifically related to the presence of HBsAg in the sample, the same will not react any more in the assay having been neutralized by the antibody.
If at contrary the positivity of the sample is not abolished by the neutralization reaction, this reactivity is not due specifically to the presence of HBsAg in the sample, but to some interfering substance.
The device has to be used in combination with the product code SAG1.CE for the determination of HBsAg in human sera and plasma.
The sample, whose repeatedly positivity for HBsAg has to be confirmed, is premixed with a reagent containing high titer anti HBsAg antibodies that will neutralize the antigen is really present in the sample.
The neutralized sample is then tested for HBsAg according to the procedure reported for the specific device.
If the positivity in the first screening test is specifically related to the presence of HBsAg in the sample, the same will not react any more in the assay having been neutralized by the antibody.
If at contrary the positivity of the sample is not abolished by the neutralization reaction, this reactivity is not due specifically to the presence of HBsAg in the sample, but to some interfering substance.
- Aach R.D., Grisham J.W., Parker S.W.. Detection of Australia antigen by radioimmunoassay. Proc.Natl.Acad.Sci..USA, 68:1956, 1971.
- Blumerg B.S., Suinick A.I., London W.T.. Hepatitis and leukemia: their relation to Australia antigen. Bull.N.Y.Acad.Med.. 44:1566, 1968.
- Boniolo A., Dovis M., Matteja R.. The use of enzymelinked immunosorbent assay for screening hybridoma antibodies against hepatitis B surface antigen. J.Immunol.Meth.. 49:1, 1982.
- Caldwell C.W., Barpet J.T.. Enzyme immunoassay for hepatitis B and its comparison to other methods. Cli.Chim.Acta 81: 305, 1977
- Fazekas S., De St.Groth, Scheidegger D.. production of monoclonal antibodies: strategy and tactics. J.Immunol.Meth.. 35: 1, 1980
- Reesink H.W.. et al.. Comparison of six 3rd generation tests for the detection of HBsAg. Vox.Sang.. 39:61, 1980
- Rook G.A.W.. Chromogens for the enzyme-linked immunosorbent assay (ELISA) using horseradish peroxidase. Lepr.Rev. 52: 281, 1981
- Schroder J.. Monoclonal antibodies: a new tool for reasearch and immunodiagnostic. Med.Biol.. 58: 281, 1981
- Wolters G. et al.. Enzyme-linked immunosorbent assay for hepatitis B surface antigen. J.Infect.Dis.. 136 suppl.: 311, 1977