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Test Code HBSAG Hepatitis B Surface Antigen (HBsAg), LAB471


Sandwich Immunoassay Chemiluminometric

Performing Laboratory

St. Luke's Hospital Cedar Rapids

Specimen Requirements


Preferred: Gold-top serum gel tube or plain, red-top tube

Acceptable: Green-top (lithium heparin or sodium heparin) tube or lavender-top (EDTA) tube 

Specimen Volume: 250 uL of serum or plasma 

Stability: Store samples at 2 to 8°C if not tested within 24 hours of collection.  Samples may be stored in primary tubes, stoppered and upright at all times at 2 to 8°C up to 7 days.  Aliquoted samples may be stored at 2 to 8°C up to 14 days.  Freeze samples, devoid of red blood cells, at or below -20°C for up to 180 days.  Thoroughly mix thawed samples and centrifuge at 10,000 g for 2 minutes before using.

Note:  This assay is affected by biotin interference.


Reference Values


Day(s) Test Set Up

Monday through Friday

Test Classification and CPT Coding


Useful For

Hepatitis B surface antigen (HBsAg) is a distinctive serological marker of acute or chronic hepatitis B infection.  HBsAg is the first antigen to appear following infection with hepatitis B virus and is generally detected 1 to 10 weeks before the onset of clinical symptoms.  HBsAg assays are routinely used to diagnose suspected HBV infection and to monitor the status of infected individuals to determine whether the infection has resolved or the patient has become a chronic carrier of the virus.