In ELISA TEST substance used is

Options

A. Endonudease
B. Ligase
C. Peroxidase
D. Polymerase

Answer

**Step-by-Step Solution:**

1. **Understanding ELISA**: ELISA stands for Enzyme-Linked Immunosorbent Assay. It is a biochemical technique used to detect the presence of an antibody or an antigen in a sample.

2. **Principle of ELISA**: The test is based on the principle of antigen-antibody interaction. In this assay, an antigen is attached to a solid surface, and a sample containing antibodies is added. If the antibodies are present, they will bind to the antigen.

3. **Detection Mechanism**: Since both antigens and antibodies are colorless, a detection method is necessary to visualize the interaction. This is where enzymes come into play.

4. **Common Enzymes Used**: The two most commonly used enzymes in ELISA tests are:
- **Horseradish Peroxidase (HRP)**: This enzyme catalyzes reactions that produce a color change, allowing for detection.
- **Alkaline Phosphatase (AP)**: This enzyme also produces a color change or fluorescence, which can be measured.

5. **Analyzing the Options**:
- **Endonuclease**: This enzyme cuts DNA within a sequence and is not used in ELISA. (Incorrect)
- **Ligase**: This enzyme is used to join DNA fragments and is not relevant to ELISA. (Incorrect)
- **Peroxidase**: This refers to horseradish peroxidase, which is indeed used in ELISA. (Correct)
- **Polymerase**: This enzyme is involved in DNA replication and transcription and is not used in ELISA. (Incorrect)

6. **Conclusion**: The correct answer is **Peroxidase**, specifically horseradish peroxidase (HRP), which is used as a test substance in the ELISA test.

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