Question

CaCl2 is often associated with which transformation method?

a. Sonic transformation

b. Chemical transformation

c. Electro-transformation

d. Biolistic transformation

Answer 1

CaCl2 is associated with chemical transformation.

It is a method of transforming a bacteria(E.coli) by introducing foreign DNA by using CaCl2 and a heat shock which stimulate the entry of DNA into the bacterial cell.

In this method, E.coli which are in log phase of their life cycle in-vitro are suspended in ice cold 50mM CaCl2 solution and incubated for upto 30 minutes followed by a brief heat shock at 42°C for 2 minutes.

Cohen et al. showed that CaCl2 treated E.coli cells are effective recipient for foreign plasmid DNA.