What is the purpose of using a radioactive molecule (probe) in diagnosing diseases through PCR?

What is the purpose of using a radioactive molecule (probe) in diagnosing diseases through PCR?
  1. To detect the presence of pathogen
  2. To detect mutated genes
  3. To detect antigens in ELISA
  4. To detect antibodies synthesized against pathogen

Solution

A single stranded DNA or RNA tagged with a radioactive molecule (probe) is used to hybridize to its complementary DNA in a clone of cells, which is then detected using autoradiography. The clone having the mutated gene will not appear on the photographic film, as the probe will not have complementarity with the mutated gene.

Asked in: NCERT

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