Test Catalog

Test ID: HBGCD    
Hepatitis B Surface Antigen for Cadaveric or Hemolyzed Specimens, Serum

Method Description Describes how the test is performed and provides a method-specific reference

Specimens are first screened by the Genetic Systems hepatitis B surface antigen (HBsAg) 3.0 EIA. All reactive results are confirmed by the Genetic Systems HBsAg Confirmatory Assay 3.0 (HBsAg Neutralization) at an additional charge.



The Bio-Rad GS HBsAg EIA 3.0 is a qualitative third generation enzyme immunoassay which uses mouse monoclonal antibodies to detect anti-HBsAg in human serum or in cadaveric serum specimens. Wells of a microwell strip plate are coated with mouse monoclonal antibody to HBsAg (anti-HBs). Patient serum and appropriate controls are added to the wells and incubated with bound antibody. If HBsAg is present it will bind to the antibody and not be removed by washing. The strips are washed to remove any unbound material. Washing is followed by the addition of conjugate solution (peroxidase-conjugated mouse monoclonal antibodies directed against HBsAg). The conjugate solution will bind to the antibody-HBsAg complex, if present. Unbound conjugate is removed by a wash step. Next, working 3,3',5,5'-tetramethylbenzidine (TMB) solution is added to the plate and allowed to incubate. A blue or blue-green color develops in proportion to the amount of HBsAg present in the sample. The enzyme reaction is stopped by the addition of acid, which changes the blue-green color to yellow. The absorbance values of controls and specimens are determined using a spectrophotometer with wavelength set at 450 nm.(Package insert: Genetic Systems HBsAg 3.0 EIA. Bio-Rad Laboratories; 02/2019)


HBsAg Confirmation:

The repeatedly reactive specimen is incubated with HBsAg confirmatory reagent (human antibody to HBsAg). If HBsAg is present in the specimen, it will be neutralized by the HBsAg confirmatory reagent. The treated specimen is re-assayed using the Genetic Systems HBsAg 3.0 EIA assay. The neutralized HBsAg is prevented from binding to the HBsAg antibody-coated microwells, which results in a reduction of signal. A non-neutralized control of the specimen (treated with HBsAg-negative control [human] in place of the HBsAg confirmatory reagent) is tested in parallel to the neutralized specimen for comparison of signal. Genetic Systems HBsAg EIA 3.0 repeatedly reactive specimens are confirmed as positive by the Genetic Systems HBsAg Confirmatory Assay 3.0 if the reduction in signal of the neutralized specimen is greater than or equal to 50% of the corresponding non-neutralized specimen and the non-neutralized specimen signal is greater than or equal to the assay cutoff.(Package insert: Genetic Systems HBsAg Confirmatory Assay 3.0. Bio-Rad Laboratories; January 2009)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday, Thursday

Report Available The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 7 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location Indicates the location of the laboratory that performs the test