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Test ID: EAG
Hepatitis Be Antigen, Serum

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

This test uses monoclonal antibodies to hepatitis Be antigen (HBeAg) as the basis for this EIA. The assay is a direct, noncompetitive test based on the use of polystyrene microwells coated with mouse monoclonal antibodies to HBeAg. An enzyme tracer containing horseradish peroxidase-labeled mouse monoclonal antibody to HBeAg detects any captured HBeAg from the patient's sample. The monoclonal antibodies are of the IgG1, kappa class and are directed to the secreted form of HBeAg.

 

In the assay procedure, patient samples and controls are incubated with incubation buffer in antibody-coated microwells. If HBeAg is present in a sample or control, it binds to the antibody. Excess sample is removed by a wash step, and the enzyme tracer is then added to the microwells and allowed to incubate. The enzyme tracer binds to any antigen-antibody complexes present in the microwells. Excess enzyme tracer is removed by a wash step, and a chromagen/substrate solution is added to the microwells and allowed to incubate. If a sample contains HBeAg, the bound enzyme (horseradish peroxidase) chemically reduces the substrate peroxide, which concurrently oxidizes the chromogen tetramethylbenzidine (TMB) to a blue color (650 nm). The blue color turns yellow (450 nm) after addition of the stop solution. If a sample does not contain HBeAg, the microwell will be colorless after the chromogen/substrate solution is added and will remain colorless after the stop solution is added. Color intensity, which is measured spectrophotometrically, is indicative of the presence of HBeAg. Absorbance value readings for patient samples are compared to a cutoff value determined from the mean absorbance of the calibrator. (Package insert: Enzyme immunoassay for the detection of hepatitis Be antigen (HBeAg) in human serum or plasma. DiaSorin S.p.A. Saluggia, Italy)

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

Monday through Friday; Varies

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

1 day

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

4 days

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

7 days

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

Rochester