Redioimmunoassay MCQ Questions and Answers
Redioimmunoassay MCQ with Answers
1. What is a radioimmunoassay intended to measure?
(1) RIA measures the concentration of antigen by the use of antibodies.
(2) RIA measures the concentration of antibody by the use of antigen.
(3) RIA measures the concentration of protein by the use of antibodies.
(4) RIA measures the concentration of insulin by the use of glycoproteins.
Answer: (1)
Explanation: Radioimmunoassay (RIA) is a sensitive technique used to measure the concentration of antigens using specific antibodies and radioactive labeling.
Read: NEET MCQ
2. What is the first step of radioimmunoassay?
(1) Antibody reagent is firstly incubated with antigens of interest.
(2) Antigen reagent is firstly incubated with antibody of interest.
(3) Radiolabeled antigens are added in the well.
(4) Unlabeled antigens are added in the well.
Answer: (1)
Explanation: In RIA, the first step typically involves incubating the antibody with the antigen of interest to form a complex.
3. How many different types of radioimmunoassay are there?
(1) Four
(2) Two
(3) One
(4) Three
Answer: (2)
Explanation: There are two main types of RIA: competitive and non-competitive assays.
4. What is tracer in radioimmunoassay?
(1) Radioactive antigen
(2) Unlabeled antigen
(3) Radiolabeled antibody
(4) Unlabeled antigen
Answer: (1)
Explanation: The tracer in RIA is usually a radiolabeled antigen that competes with the sample antigen for binding to antibodies.
5. Who discovered the radioimmunoassay?
(1) Yalow and Berson
(2) Eva Engvall and Peter Perlman
(3) Fahey and McKelvey
(4) None of these
Answer: (1)
Explanation: RIA was discovered by Rosalyn Yalow and Solomon Berson in the 1950s. Yalow later won the Nobel Prize for this work.
6. Which isotope is used in radioimmunoassay?
(1) ¹²⁵I
(2) ¹⁴C
(3) ²⁴NaH
(4) ³⁶Cl
Answer: (1)
Explanation: Iodine-125 (¹²⁵I) is the most commonly used radioactive isotope in RIA due to its ideal half-life and gamma emission.
7. Which of the following are the components of radioimmunoassay?
(1) Radiolabeled antigens
(2) Monoclonal antibodies
(3) Unlabeled antigens
(4) All of the above
Answer: (4)
Explanation: RIA involves radiolabeled antigens (tracers), unlabeled antigens (sample), and specific antibodies—making all the options correct.
8. How many micrograms of antigen can be detected in radioimmunoassay?
(1) 0.001 μg/ml
(2) 0.1 μg/ml
(3) 0.01 μg/ml
(4) 1 μg/ml
Answer: (1)
Explanation: RIA is extremely sensitive and can detect as little as 0.001 micrograms per milliliter (μg/ml) of antigen.
9. Which of the following is not an application of radioimmunoassay?
(1) RIA is used to determine insulin and growth hormone.
(2) Radioimmunoassay (RIA) can detect drugs such as Heroin & Morphine.
(3) RIA is used for determination of folic acid and vitamin B12.
(4) RIA is used to determine the concentration of glycoproteins.
Answer: (4)
Explanation: RIA is not commonly used for glycoprotein concentration. It’s mostly applied to detect small molecules like hormones, vitamins, and certain drugs.
What is Radioimmunoassay (RIA)
Radioimmunoassay (RIA) is a highly sensitive and specific laboratory diagnostic technique that widely used to detect and quantify substances at the molecular level in biological samples, and is an essential tool in various medical disciplines, from endocrinology to biomedical research.
Radioimmunoassay (RIA) developed in the 1960s by scientists Solomon Berson and Rosalyn Yalow, radioimmunoassay has revolutionized the field of medical research and diagnosis. Through the use of antibodies and radioisotopes, it allows the measurement of substances present at extremely low concentrations in biological fluids such as blood or urine, something previously impossible with other available techniques.
The basic principle of RIA involves competition between a radiolabeled substance of interest (antigen) and the same unlabeled substance, present in the patient’s sample, for a limited number of specific binding sites provided by antibodies. These antibodies have a high affinity for the substance being measured. By separating the bound fraction from the unbound fraction and measuring the radioactivity, the concentration of the substance in the sample can be determined.
For example, if one wanted to measure the amount of a specific hormone in the blood, a known amount of that radiolabeled hormone would be added to the blood sample. Then, antibodies specific to that hormone would be added. These antibodies would bind to both the radiolabeled hormone and the hormone present in the blood sample. After a separation process, the amount of radioactivity would be proportional to the amount of hormone in the sample.
One of the greatest benefits of RIA is its high sensitivity. It is capable of detecting substances at concentrations as low as parts per billion or even parts per trillion. This sensitivity has been crucial in detecting low levels of hormones, drugs, and other biologically active substances in the body.
However, as with all techniques, radioimmunoassay has its limitations. The main one is the use of radioisotopes, which have a half-life and eventually decay, limiting the time during which they can be used. Furthermore, handling radioactive materials requires special precautions and strict regulations to ensure the safety of both laboratory personnel and the environment. On the other hand, technological advances have led to the development of similar techniques, such as the enzyme-linked immunosorbent assay (ELISA), which does not require radioisotopes and relies on enzymatic reactions to produce a detectable signal.
Radioimmunoassay remains a valuable technique and is used in numerous medical and research applications. It has advanced our understanding of various pathologies, providing information on the concentration of substances that was previously inaccessible. In the field of endocrinology, for example, RIA has been instrumental in measuring hormones under normal and pathological conditions, aiding in the diagnosis and monitoring of diseases.
