Q. 38 Discuss briefly how a probe is used in molecular diagnostics.

Early detection of a disease is not possible by conventional diagnostic methods. So, some techniques have been implanted for early diagnosis like PCR, recombinant DNA technology and ELISA.

In recombinant DNA technology, a probe is used. It is allowed to hybridise to its complementary DNA in the clone of cells. The cells are then detected by autoradiography.

The cell with mutated gene will not be observed on the photographic flim because, the probe will not have complementarity with the mutated gene.