A patient screens positive for HIV antibodies by ELISA. Which confirmatory technique directly identifies antibodies bound to specific viral proteins separated by electrophoresis?

• A Southern blot
• B Northern blot
• C Southwestern blot
• D Western blot ✓

Explanation

Western blotting separates proteins by SDS-PAGE, transfers them to a membrane, and probes with the patient's serum to detect antibodies bound to specific viral antigens such as gp120 and p24. It was the classical confirmatory test after a reactive ELISA. Southern blot detects DNA, Northern blot detects RNA, and Southwestern blot detects DNA-binding proteins, so none of these can identify antibody binding to viral protein bands.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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