Which one of the following techniques is not useful for detecting cancer of internal organs?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → ELISA
Cancers of the internal organs cannot be seen from outside. They are found with imaging techniques that show the inside of the body.
(1) Radiography — A technique useful for detecting cancer of internal organs. It uses X-rays to show the organs.
(2) ELISA — Not a technique useful for detecting cancer of internal organs. It is an antigen–antibody test. NCERT names it for finding a pathogen such as HIV, not for imaging organs.
(3) Computed tomography — A technique useful for detecting cancer of internal organs. It uses X-rays to build a three-dimensional image of the inside of an organ.
(4) Magnetic resonance imaging — A technique useful for detecting cancer of internal organs. It uses strong magnetic fields and non-ionising radiation to find pathological and physiological changes.
Note: A similar question was also asked in CUET (UG) 2025 on 29-05-2025 (Slot 1).
NCERT Extract:
Cancer – “… Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs.”
Molecular Diagnosis – “… ELISA is based on the principle of antigen-antibody interaction.”