Which diagnostic technique uses fluorescently labeled probes to detect specific DNA sequences in cells or tissue?

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Multiple Choice

Which diagnostic technique uses fluorescently labeled probes to detect specific DNA sequences in cells or tissue?

Fluorescence in situ hybridization uses fluorescently labeled DNA probes that are complementary to a specific DNA sequence. In fixed cells or tissue sections, these probes hybridize to their target sequences, and the fluorescent signal visible under a microscope shows exactly where that DNA sequence sits within the chromosomes or nuclei. This makes it possible to localize genes, detect chromosomal abnormalities such as deletions, duplications, or translocations, and even identify certain pathogens in tissue samples, all within their cellular context. Flow cytometry, by contrast, analyzes physical and chemical characteristics of cells in suspension using fluorescently labeled antibodies, not DNA sequences. PCR amplifies a DNA sequence from extracted DNA but does not show its location inside cells or tissues. Western blot detects proteins rather than DNA.

Fluorescence in situ hybridization uses fluorescently labeled DNA probes that are complementary to a specific DNA sequence. In fixed cells or tissue sections, these probes hybridize to their target sequences, and the fluorescent signal visible under a microscope shows exactly where that DNA sequence sits within the chromosomes or nuclei. This makes it possible to localize genes, detect chromosomal abnormalities such as deletions, duplications, or translocations, and even identify certain pathogens in tissue samples, all within their cellular context.

Flow cytometry, by contrast, analyzes physical and chemical characteristics of cells in suspension using fluorescently labeled antibodies, not DNA sequences. PCR amplifies a DNA sequence from extracted DNA but does not show its location inside cells or tissues. Western blot detects proteins rather than DNA.

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