Describe any three vectors less method of introducing the rDNA into a competent host cell?
The three vectors less method of introducing the rDNA into a competent host cell are: i) Transformation: The bacterial cell is first treated with the specific concentration of divalent cation e.g., Ca2+ so that they can be competent enough to take up the DNA in the plasmid. The calcium ions increase the efficiency of DNA to enter into a bacterium through pores in its cell wall. By the process of incubating the cells with recombinant DNA on ice, then placing them at 420 C, and then again putting them back into ice the recombinant DNA can then be forced into cells. This helps the bacteria in taking up the recombinant DNA. ii) Microinjection: With the help of a microneedle of the tip with a diameter (~ 4mm), the recombinant DNA can be injected directly into the nucleus of an animal cell. iii) Biolistic / Gene gun: The cells of the DNA that are coated with particles of gold or tungsten are bombarded with high-velocity micro-gun.
