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Test Code HBSAG Hepatitis B Surface Antigen (HBsAg) [LAB471]

Performing Laboratory

UnityPoint Finley Hospital

Test Method

Electrochemiluminescence sandwich principle: Roche cobas Pro

Specimen Requirements

  1. Serum is the specimen of choice.
  2. Lithium heparin and EDTA plasma are also acceptable sample types; however, serum is required if confirmation testing is needed.
  3. Gel tubes are acceptable.  
  4. Hepatitis B Surface Antigen specimens are stable for 6 days at 20-25°C, 14 days at 2-8°C, and 6 months at -20°C.

Reference Values

Nonreactive

 

Reactive results are preliminary and are sent out for confirmation testing.

Performance

Testing is performed 7 days a week Monday through Sunday. Routine specimen requests are completed the same day upon arrival to the laboratory. Stat requests are completed within 4 hours upon receipt. 

Useful For

The hepatitis B surface antigen, a polypeptide of varying size, is a component of the external envelope of the hepatitis B virus particle (HBV). The blood of persons infected with HBV contains, in addition to intact infectious HBV particles, smaller non-infectious “empty” envelope particles, which are formed in great excess and also contain the hepatitis B surface antigen. The detection of HBsAg in human serum or plasma indicates an infection by the hepatitis B virus. HBsAg is the first immunological marker to appear in acute hepatitis B infection and is generally present some days or weeks before clinical symptoms begin to appear. HBsAg is observed in persons with acute and chronic hepatitis B infections. HBsAg tests are part of the diagnostic algorithm used to identify persons infected with HBV and to prevent the transmission of the hepatitis B virus by blood and blood products.

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