Confirmatory test for STIs is

Options

A. ELISA
B. PCR
C. DNA hybridisation
D. all of these

Explanation

To answer the question regarding the confirmatory test for STIs (sexually transmitted infections), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding STIs**:
- STIs are infections that are primarily transmitted through sexual contact. Examples include chlamydia, gonorrhea, syphilis, and HIV.

2. **Initial Testing Procedures**:
- The first step in diagnosing STIs typically involves collecting a sample from the suspected infected individual. This could be blood, urine, or swabs from affected areas.

3. **Culture of the Sample**:
- The collected sample is cultured in a laboratory to allow any pathogens present to grow. This helps in identifying the specific organism causing the infection.

4. **Microscopic Observation**:
- After culturing, the sample is observed under a microscope. This helps in identifying any changes or specific characteristics of the pathogens.

5. **Staining the Sample**:
- The cultured sample is stained using specific stains that can highlight certain features of the pathogens, making them easier to identify under a microscope.

6. **Detection of Antibodies and Antigens**:
- The next step involves detecting specific antibodies or antigens related to the STI. This is crucial for confirming the presence of the infection.

7. **Methods for Detection**:
- There are several methods used for the detection of STIs:
- **ELISA (Enzyme-Linked Immunosorbent Assay)**: A common test used to detect antibodies in the blood.
- **PCR (Polymerase Chain Reaction)**: A highly sensitive technique that amplifies DNA, allowing for the detection of even small amounts of pathogen DNA.
- **DNA Hybridization**: This method involves the binding of DNA strands to detect specific sequences associated with pathogens.

8. **Conclusion**:
- The confirmatory tests for STIs include ELISA, PCR, and DNA hybridization. Therefore, the correct answer to the question is that the confirmatory tests for STIs are ELISA, PCR, and DNA hybridization.

### Final Answer:
The confirmatory tests for STIs are ELISA, PCR, and DNA hybridization.

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