A method of vectorless DNA transfer is:

Options

A. microinjection
B. electroporation
C. biolistics
D. all of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a method of vectorless DNA transfer. This means we are looking for techniques that do not rely on vectors (like plasmids) to introduce foreign DNA into host cells.

2. **Identifying Methods of DNA Transfer**: The video mentions several methods of DNA transfer:
- Microinjection
- Electroporation
- Biolistic method (Gene-Gun method)

3. **Analyzing Each Method**:
- **Microinjection**: This technique involves directly injecting DNA into the nucleus of a cell using a fine needle or pipette. It does not require a vector.
- **Electroporation**: This method uses electrical pulses to create temporary pores in the cell membrane, allowing DNA to enter the cell without a vector.
- **Biolistic Method**: Also known as the Gene-Gun method, this involves bombarding cells with high-velocity microparticles coated with DNA, which does not involve a vector.

4. **Conclusion**: All three methods mentioned (Microinjection, Electroporation, and Biolistic method) are vectorless methods of DNA transfer. Therefore, the correct answer to the question is "All of these."

5. **Final Answer**: The method of vectorless DNA transfer is: **All of these** (Microinjection, Electroporation, Biolistic method).

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