Hepatitis B Surface Antigen (HBsAg) with Reflex Confirmation Test
This test measures Hepatitis B Surface Antigen (HBsAg) in a serum sample. If the result is positive, the laboratory automatically runs a confirmatory test based on the manufacturer's FDA-approved recommendations.
About this test
Hepatitis B Surface Antigen usually appears in the blood one to six months after exposure to the Hepatitis B virus and tends to peak around the time symptoms begin. In most people it clears within one to three months.
The test is run on a 2 mL serum sample using an immunoassay method. Because a positive screening result on its own does not confirm infection, this product includes a reflex step: if the surface antigen result is positive, confirmatory testing is performed automatically on the same sample, following the test kit manufacturer's FDA-approved recommendations, rather than requiring a separate order.
Test details
| Collection | Quest patient service center |
|---|
Quest resources
Additional details
What this test looks at
The test reports two things: whether Hepatitis B Surface Antigen is present, and — only if that first result is positive — the outcome of a confirmatory test run automatically on the same sample. This reflex step means a positive screen does not require a second, separate order.
This test isn't part of the Celio Health store at the moment, so it can't be ordered or requested here. The test menu lists everything that can.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures Hepatitis B Surface Antigen (HBsAg) in a serum sample, an antigen that typically appears one to six months after exposure to Hepatitis B virus and peaks around the onset of symptoms.
How is the sample collected?
The test uses a 2 mL serum sample from a routine blood draw at a Quest Diagnostics patient service center.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
What happens if my HBsAg result is positive?
The laboratory automatically runs a confirmatory test on the same sample, following the manufacturer's FDA-approved recommendations, so a positive screen does not require a separate order.
Is HBsAg the same as "Hep B" or "Australian Antigen"?
Yes. Quest lists this test under several names, including Hep B, HBsAg and Australian Antigen; they all refer to the same Hepatitis B Surface Antigen measurement.