Question

Explain any two methods of vectorless gene transfer.

Hint:

Any two: micro-injection into the nucleus, biolistics (gene gun), electroporation.

Answer 1

Step 1: Understanding the Concept:
In vectorless (direct) gene transfer the desired gene is put into the host cell without using a plasmid or a virus as the vector.
The DNA is pushed or driven into the cell by a physical method.

Step 2: Method 1: Micro-injection:
Here the recombinant DNA is injected directly into the nucleus of a single cell with a very fine glass needle (micro-pipette).
The cell is held in place by a holding pipette while this is done.
This is used for animal cells, for example to make transgenic animals from fertilised eggs.

Step 3: Method 2: Biolistics or gene gun:
Tiny particles of gold or tungsten are coated with the DNA.
These particles are shot at high speed into the target cells, often plant cells, using a gene gun.
The DNA then enters the cell and may join the host genome.

Final Answer:
Two methods of vectorless gene transfer are micro-injection and the biolistic (gene gun) method. Electroporation is another one.