A scientist wants to insert a modified DNA directly into the nucleus of the animal cell . Which of the techniques will be best suited ?

Options

A. Gene gun
B. Disarmed pathogen
C. Cloning vector
D. Microinjection

Answer

To solve the question of which technique is best suited for inserting modified DNA directly into the nucleus of an animal cell, we can analyze the options provided:

### Step-by-Step Solution:

1. **Understanding the Requirement**: The scientist needs to insert modified DNA directly into the nucleus of an animal cell. This requires a technique that can effectively deliver DNA into the nucleus.

2. **Evaluating the Techniques**:
- **Gene Gun**: This technique is primarily used for plant cells. It involves shooting DNA-coated particles into cells but is not suitable for animal cells. Therefore, this option is incorrect.

- **Disarmed Pathogen**: This method involves using a pathogen (like Agrobacterium tumefaciens) to transfer DNA. However, it is an indirect method and not specifically designed for direct insertion into the nucleus of animal cells. Thus, this option is also incorrect.

- **Cloning Vector**: Cloning vectors, such as PBR322, are typically used for cloning DNA fragments and do not directly insert modified DNA into the nucleus of animal cells. Hence, this option is incorrect as well.

- **Microinjection**: This technique involves using a fine needle (microsyringe) to inject DNA directly into the nucleus of a cell. It is a well-established method for introducing DNA into animal cells and is the most suitable option for the requirement stated in the question.

3. **Conclusion**: Based on the analysis, the best technique for inserting modified DNA directly into the nucleus of an animal cell is **Microinjection**.

### Final Answer:
**Microinjection** is the best-suited technique for inserting modified DNA directly into the nucleus of an animal cell.