Question

ELISA is based on the principle of:

• A. Antigen – Antigen interaction
• B. B-cells and T-cells interaction
• C. Antigen – Antibody interaction
• D. T-cell – Antibody interaction

Answer 1

The Correct Option is C

ELISA, which stands for Enzyme-Linked Immunosorbent Assay, is a common laboratory technique used to detect and measure antibodies or antigens in a sample. The fundamental principle of ELISA is based on Antigen – Antibody interaction. This interaction is highly specific, allowing for the detection of particular proteins. The process involves the following key steps:

1. An antigen or antibody is immobilized on a solid surface. 
2. A sample containing antibodies (or antigens) is added, where it will bind to the immobilized antigen (or antibody) if the target is present.
3. An enzyme-linked secondary antibody is then added, which binds to the primary antibody (if detecting antigens) or directly to the antigen (if detecting antibodies).
4. A substrate is introduced, which reacts with the enzyme to produce a detectable signal, typically a color change.

The specificity and sensitivity of the Antigen – Antibody interaction in ELISA make it a powerful tool in diagnostics and research, particularly in detecting diseases, allergens, and hormones.

Answer 2

ELISA (Enzyme-Linked Immunosorbent Assay) is a widely used laboratory technique that is based on the interaction between antigens and antibodies. It is used for detecting and quantifying substances such as proteins, hormones, or antibodies in a sample. The principle behind ELISA involves the specific binding of an antibody to its corresponding antigen, which allows the detection of the presence of the antigen in a sample when a color change or signal is produced, typically through an enzyme-substrate reaction.