Diagnostic Test Directory

Virology Laboratory

Hepatitis B virus (HBV) surface antigen - serum or plasma specimen

  • Synonyms: HBsAg, Hepatitis B Virus Surface Antigen
  • LIS Mnemonic: HBVSAG


    PREFERRED: Serum is the preferred specimen. Collect blood in a 4 ml Gold Serum Separator Tube-Clot Activator & Gel. REMARK: Plasma is an acceptable alternative specimen. Blood can be collected in

    Volume Required

    4 ml of blood

    Minimum Required

    2 ml of blood


    A total of 2-4 ml of blood (for every 2-3 Hepatitis and HIV tests ordered) should be collected. For the CHOP enterprise, submit blood specimens as soon as possible at room temperature to Central Laboratory Services. For outside clients, it is recommended that serum or plasma specimens be removed from the clot, red blood cells, or separator gel as soon as possible after collection and before shipping specimens. When shipping serum or plasma specimens, package and label specimens in complian


    Serum or plasma specimens should be stored for no longer than 3 days at room temperature or 7 days at 2-8C following specimen collection and separation from clot, red blood cells, or separator gel. If

    Unacceptable conditions

    Do not use serum or plasma specimens that are heat-inactivated, pooled, grossly hemolyzed, or contain obvious microbial contamination. Performance has not been established for the use of cadeveric specimens or the use of boody fluids other than human serum or plasma.

    Specimen Handling

    Unprocessed blood specimens should routinely be refrigerated at 4C upon arrival in the laboratory. O

Days Performed

Monday thru Friday



Reflex Testing

Hepatitis B surface antigen confirmation assay. All specimens that test repeatedely positive for Hepatitis B surface antigen by the screening immunoassay must be confimed by a neutralization assay.


87340 (initial screening),87341 (confirmation assay, if necessary)


Chemiluminescent microparticle immunoassay

Disease Information


A test for HBsAg is indicated as an aid in the laboratory diagnosis of acute, chronic, or resolved hepatitis B viral infection. Detection of HBsAg indicates the presence of HBV but does not distinguish between acute and chronic infection. During acute HBV infection, HBsAg appears 3-5 weeks before the onset of symptoms, peaks during the acute phase of the disease, and slowly declines to undetectable levels within 4-6 months. Persistance of HBsAg for 6 months or longer after acute illness is indicative of chronic infection. HBsAg can be detectable for life in most chronically infected individuals; only 1-2% of chronic HBV carriers become negative for HBsAg each year. The HBsAg assay also may be used to test for HBV infection in pregnant women. Prenatal testing has been recommended so that newborns from mothers who are HBV carriers may receive appropriate prophylactic treatment.


HBV surface antigen is the earliest indicator of the presence of acute infection; it is also indicative of chronic infection. A hepatitis B core IgM

Reference Values

Negative or non-reactive for hepatitis B Virus (HBV) surface antigen.

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