Question

DNA being hydrophilic cannot pass through the cell membranes of a hot cell. Explain how does recombinant DNA get introduced into the host cell to transfrom the latter.

Answer 1

Introduction of rDNA into host cell.
(i) Heat shock method- In this method, DNA is treated with a specific concentration of a divalent cation, such as calcium which increases the efficiency with which DNA enters the bacterium through pores in its cell wall.
The rDNA is forced into the cell by incubating the cell with rDNA on ice followed by placing them briefly at `42^(@)`C (heat shock) and then patting them back on ice ?
(ii) Micro Injection- In this method, the rDNA is directly injected into the nucleus of an animal cell.
(iii) Gene `Gun// Biolistics- In this method, cells are bombarded with hifh velocity microparticles of gold or tungsten coated with DNA.