Transformation is the process of introduce DNA from reaction mixture into host cells resulting uptake and incorporation of exogenous genetic material. In cloning process, it is used to transfer recombinant vector which has gene of interested into the host cell to clone that recombinant DNA. In order for the host cell to take up the recombinant vector, the host cell have made competent first. There are two methods which are electroporation and heat shock transformation.
https://www.boundless.com/microbiology/textbooks/boundless-microbiology-textbook/microbial-genetics-7/genetic-transfer-in-prokaryotes-81/bacterial-transformation-442-6842/
Electroporation
This involve the use of high voltage electric pulses to induce the permeability of membrane of cell so DNA can translocate across cell wall and cell membrane. This method usually used to introduce foreign DNA into the bacteria, yeast and etc. Electroporation is more effective and less cumbersome than chemical transformation.The better results obtain when using fast growing cells, after stop the reaction cause temperature decrease then the growth of cell should as fast as possible and all post growing rapidly.
The picture on left side shown the process of electroporation to make the bacteria competent and the picture on right side shown the general electroporation principle.
Chemical Transformation
This involve the use of chemical solution and heat to make the cells able to take up the recombinant vector. This involve the use of chemical solution and heat to make the cells able to take up the recombinant vector. The bacteria cells suspended in cold buffer that contains salts and calcium chloride. Typically, the bacteria cells was stored frozen. The cells thawed and added DNA when needed. After that, the cell warmed which caused transformation occur. Dilution of the transformed cells and plated onto media for selection of transformants. The picture shown the procedure of chemical transformation by using heat-shock.This method work best at 42 degree celcius bath rather than 37 degree celcius.
|