NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Biology
- Chapter
- Chapter
NEET 2026 · Biology · Chapter
Why are conventional diagnostic methods, such as routine serum and...
Why are conventional diagnostic methods, such as routine serum and urine analysis, considered ineffective for the early detection of infectious diseases?
Options
- AThey detect the pathogen only when its concentration is already very high and disease symptoms have appeared.
- BThey require the use of a single-stranded DNA or RNA probe tagged with a radioactive molecule.
- CThey rely on the principle of antigen-antibody interaction, which is specific only to viral infections.
- DThey involve the amplification of the pathogen's nucleic acid, which is a highly time-consuming process.
Correct answer
A. They detect the pathogen only when its concentration is already very high and disease symptoms have appeared.
Step-by-step solution
Conventional diagnostic methods such as routine serum and urine analysis are not sensitive enough to detect the presence of a pathogen when its concentration in the body is very low. By the time these methods can detect the pathogen, its concentration has already become very high, and the patient has typically started exhibiting symptoms of the disease. For early detection, modern molecular diagnostic techniques like PCR (Polymerase Chain Reaction) and ELISA (Enzyme-Linked Immunosorbent Assay) are used because they can detect very low amounts of pathogens.
Answer: They detect the pathogen only when its concentration is already very high and disease symptoms have appeared.
Answer: They detect the pathogen only when its concentration is already very high and disease symptoms have appeared.