A research laboratory uses Southern blotting to detect a specific gene deletion. Which sequence of steps correctly describes the Southern blot procedure?

• A DNA extraction → restriction enzyme digestion → gel electrophoresis → membrane transfer → hybridization with labeled DNA probe ✓
• B RNA extraction → electrophoresis → membrane transfer → hybridization with DNA probe
• C Protein extraction → SDS-PAGE → membrane transfer → incubation with antibody
• D DNA extraction → PCR amplification → agarose gel staining → ethidium bromide visualization

Explanation

Southern blotting detects specific DNA sequences in genomic DNA. The procedure involves: extraction and restriction enzyme digestion of DNA, separation of fragments by size via agarose gel electrophoresis, alkaline denaturation and capillary or electrophoretic transfer (blotting) of single-stranded DNA fragments onto a nylon or nitrocellulose membrane, and hybridization with a labeled complementary DNA probe. Detection reveals fragments of specific sizes containing the gene of interest, making deletions evident by absent or size-shifted bands.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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