Transfer of desired genes from one organism into another is an important aspect of genetic engineering.
Gene transfer is achieved by two kinds of transfer methods:
(i) Indirect method through vectors or carriers and
(ii) Direct or vector less transfer method
Vectorless Gene Transfer : Foreign genes can also be transferred directly by the following methods:
(a) Electroporation : It creates transients ( temporary pores) in the plasma membrane to facilitate entry of foreign DNA.
(b) Chemical mediated genetic transformation: It involves certain chemicals such as polyethylene glycol (PEG), that help in the uptake of foreign DNA into host cells.
(c) Microinjection : It is the introduction of foreign genes into plant or animal cells using microinjection or glass needles.
(d) Particle gun/ Biolistic method: It is a technique in which tungsten or gold particle coated with foreign DNA are bombarded into target cells to facilitate entry of the foreign genes.
(e) Liposome mediated gene transfer : In this method DNA encloses within lipid begs. These lipid begs fused with protoplast.
