Question

ELISA is based on the principle of:

• A. Antigen - antibody interaction
• B. PCR
• C. Radioactive molecule
• D. Amount of DNA

Hint:

ELISA is used to detect the presence of antigens or antibodies based on their specific interaction.

Answer 1

The Correct Option is A

Enzyme-linked immunosorbent assay (ELISA) is a laboratory technique used to detect and quantify substances such as peptides, proteins, antibodies, and hormones. The principle behind ELISA is the antigen-antibody interaction.
Step 1: Analyzing the options.
- Antigen - antibody interaction (Option 1): This is correct. ELISA is based on the specific binding of an antigen to its corresponding antibody. The antigen is typically attached to a surface, and the antibody is detected using an enzyme-linked secondary antibody.
- PCR (Option 2): PCR (Polymerase Chain Reaction) is a method for amplifying DNA, not related to ELISA.
- Radioactive molecule (Option 3): ELISA typically uses enzymes for detection, not radioactive molecules.
- Amount of DNA (Option 4): ELISA does not directly measure the amount of DNA, but rather the interaction between antigen and antibody.
Step 2: Conclusion.
ELISA is based on the principle of antigen-antibody interaction.
Final Answer: \[ \boxed{\text{The correct answer is (1) Antigen - antibody interaction.}} \]