Question

Assertion: Using conventional method of diagnosis (serous and urine analysis etc) early detection in not possible.
Reason: Recombinant DNA technology, PCR and ELISA are some of the techniques that serve the purpose of early diagnosis.

Answer 1

Many conventional diagnostic tools are inaccurate, time-consuming, laborious and expensive.

With advances in biotechnology, early diagnosis and prevention are possible now.

To detect mutated genes DNA probes are used. A single-stranded DNA or RNA tagged with a radioactive molecule or a probe is allowed to hybridize to its complementary DNA in a clone of cells followed by detection by autoradiography. The clone having mutated gene will not appear on the radio graphic film because the probe will not have complementarity with the mutated gene.

PCR or polymerase chain reaction is used to detect disease at an early stage when the pathogens causing disease are few in number and are unable to produce symptoms.The test detects the presence of nucleic acid of the pathogen in body fluids, eg, detect HIV in AIDS or mycobacteria in tuberculosis

PCR is also used to detect gene mutation in cancer patients.

Enzyme-linked immunosorbent assay or ELISA is used to detect the presence of antigens, like proteins or glycoproteins, produced by pathogens and antibodies synthesized by the body against pathogens.