Which one of the following techniques serve the purpose of early diagnosis of diseases?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Enzyme linked immuno-sorbent assay
A pathogen is usually suspected only when the disease shows its symptoms. By then the pathogen has multiplied to a very high number. Conventional tests cannot find it earlier. ELISA works on the principle of antigen-antibody interaction. It detects an infection early, either by finding the antigens (proteins, glycoproteins) of the pathogen or by finding the antibodies that the body has made against it. Recombinant DNA technology and PCR are the other techniques for early diagnosis.
(1) Stool analysis — Incorrect. It is a conventional test. Like the other conventional tests, it does not detect a disease before the symptoms appear.
(2) Enzyme linked immuno-sorbent assay — Correct. It detects antigens or antibodies and so serves early diagnosis.
(3) Urine analysis — Incorrect. NCERT names it as a conventional method with which early detection is not possible.
(4) Serum analysis — Incorrect. NCERT also names it as a conventional method with which early detection is not possible.
NCERT Extract:
Molecular Diagnosis – “… You know that for effective treatment of a disease, early diagnosis and understanding its pathophysiology is very important. Using conventional methods of diagnosis (serum and urine analysis, etc.) early detection is not possible. Recombinant DNA technology, Polymerase Chain Reaction (PCR) and Enzyme Linked Immuno-sorbent Assay (ELISA) are some of the techniques that serve the purpose of early diagnosis.”