Question

Indirect ELISA, also known as--

• A. Double antibody sandwich (DAS) ELISA
• B. Competitive ELISA
• C. Triple antibody sandwich (TAS) ELISA
• D. dot ELISA

Hint:

Remember that "Indirect" refers to using a secondary antibody conjugated to an enzyme, meaning the detection is mediated by a second antibody layer.
This distinguishes it from Direct ELISA where the primary antibody itself is conjugated.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Enzyme-Linked Immunosorbent Assay (ELISA) is a primary plate-based assay technique used to detect and quantify proteins, antibodies, or hormones.

Step 2: Detailed Explanation:
In an Indirect ELISA:
- Antigen is immobilized on the solid phase of a microtiter plate.
- A primary antibody (from a test sample) is added to bind specifically to the antigen.
- An enzyme-linked secondary antibody (anti-species antibody) is then added to bind to the primary antibody.
- Because two distinct antibodies (primary and secondary) are used sequentially to detect the target, some historical systems and assays classify it closely with double-antibody detection methods, such as the Double antibody sandwich (DAS) ELISA.

Step 3: Final Answer:
The correct option corresponding to the question's classification is (A).