p24 antigen is a viral protein that makes up most of the viral core. Serum concentrations of p24 antigen are high in the first few weeks after infection; tests sensitive to p24 antigen are therefore useful for diagnosing very early infection when antibody levels are still low.
To determine if you are infected with human immunodeficiency virus (HIV)
A negative test for HIV antigen and/or HIV antibody usually indicates that a person does not have an HIV infection.
