Foreign DNA can be introduced into host cells using various methods:
- Microinjection: Directly injecting DNA into the nucleus of the cell using a fine glass micropipette.
- Biolistics (Gene gun method): High-velocity delivery of DNA-coated particles (e.g., gold or tungsten) into plant cells.
- Disarmed pathogen: Using genetically modified, non-virulent bacteria or viruses (e.g., Agrobacterium tumefaciens) to transfer DNA into cells.