hepatitis B surface antigen
noun
: an antigen that is usually a surface particle from the hepatitis B virus and that is found circulating in the blood serum especially of infected individuals
—abbreviation HBsAg
called also Australia antigen
Cite this Entry
“Hepatitis B surface antigen.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/hepatitis%20B%20surface%20antigen. Accessed 29 Nov. 2025.
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