Question

The treatment of bacteria with ice-cold solutions of CaCl2 and then heated to 37∘C or 42∘C is the process or method called as

Answer 1

The process is described as heat shock treatment which is an important step in transformation.it promotes the up-take of DNA from the surrounding medium which is called competence. after repeated centrifugations of the medium containing culture with 0.5m CaCl2, the pellet is dissolved in TE buffer and 0.5m CaCl2 and kept in water bath maintained at 42 c for 2min and immediately transferred to ice for few minutes.then the tube is maintained at 37c for 40minute and plated on LB Agar plates with selective antibiotics. heating at 42c opens the pores of cell wall and allows the DNA from surrounding to enter the cell while immediate cooling on ice closes the pores