Diagnosis of sexually -transmitted disease is done by

Options

A. DNA hybridisation
B. PCR
C. Elisa test
D. All these

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the methods used to diagnose sexually transmitted diseases (STDs).

2. **Identifying Diagnostic Methods**: There are several methods used for the diagnosis of STDs. Some of the prominent ones include:
- **DNA Hybridization**: This method involves making multiple copies of DNA to identify the specific pathogen responsible for the STD.
- **Polymerase Chain Reaction (PCR)**: PCR is a widely used technique that amplifies a specific segment of DNA, allowing for the detection of pathogens even in small quantities. This method is known for its speed and accuracy, making it suitable for early detection of STDs.
- **Enzyme-Linked Immunosorbent Assay (ELISA)**: This test is commonly used for diagnosing infections like HIV/AIDS, which is also a sexually transmitted disease. ELISA detects antibodies or antigens in the blood, indicating the presence of an STD.

3. **Conclusion**: The diagnosis of sexually transmitted diseases can be effectively conducted using methods such as DNA hybridization, PCR, and ELISA tests.