The use of calcium chloride for the transformation (incorporation of plasmid DNA into bacteria ) enables the binding of plasmid DNA to lipopolysaccharides (LPS) on the plasma membrane. Positively charged Ca2+ attract both the negatively charged DNA and the negatively charged groups in the LPS.
Using
heat shock for the transformation creates a pressure difference between the outside and the inside of the cell. This induces the formation of pores, through which plasmid DNA can enter the cell.
