What is the western blot test used for?

• A. Detect HIV
• B. Detect hepatitis B
• C. Detect tuberculosis
• D. Detect influenza

Answer: (A)

The test is used to confirm HIV infection by detecting antibodies to HIV proteins. It works by exposing a patient’s serum to HIV proteins and looking for a specific pattern of antibody binding. If multiple HIV-specific bands appear, it indicates infection, providing a confirmatory result after an initial positive screening test. This is why the Western blot is associated with HIV diagnosis.

Hepatitis B is typically diagnosed using tests for HBV surface antigen or antibodies (and sometimes viral DNA), not by the characteristic protein-band pattern seen in a Western blot. Tuberculosis is diagnosed mainly through sputum smear, culture, or nucleic acid tests, not Western blot patterns. Influenza is detected with rapid antigen tests or PCR, not Western blot.