In r-DNA technique which of the following technique is not used in introducing DNA into host cell

Options

A. Transduction
B. Conjugation
C. Transformation
D. Electroporation

Answer

To solve the question regarding which technique is not used in introducing DNA into host cells in the r-DNA (recombinant DNA) technique, we can analyze the different methods mentioned:

### Step-by-Step Solution:

1. **Understand the Techniques**:
- **Transduction**: This is a method where DNA is transferred from one bacterial strain to another using a viral vector. It is commonly used in genetic engineering to introduce foreign DNA into host cells.
- **Conjugation**: This is a process where DNA is transferred between two bacterial cells through direct physical contact, specifically through a structure called a conjugation tube. This method is not typically used in r-DNA technology for introducing DNA into host cells.
- **Transformation**: This process involves the uptake of free DNA from the environment by a bacterial cell. It does not require physical contact between cells and is a common method used in r-DNA techniques.
- **Electroporation**: This technique involves applying an electric field to cells to make their membranes permeable, allowing DNA to enter the cells. It is also used in r-DNA technology.

2. **Identify the Incorrect Technique**:
- Among the methods discussed, **conjugation** is the only technique that is not typically used in the r-DNA technique for introducing DNA into host cells.

3. **Conclusion**:
- The correct answer to the question is **Conjugation**.

### Final Answer:
The technique that is not used in introducing DNA into host cells in the r-DNA technique is **Conjugation**.