Genetic transformation literally means change caused by genes, and involves the insertion of a gene (donor) into an organism (from recipient) in order to change the organism’s trait.
The process of transformation has certain common features:
- The purified donor DNA is first transported across the cell membrane into the recipient “competent cells” (cells, that can take up DNA), and
- The DNA then undergoes recombination with the recipient DNA and is then expressed.
Genetic transformation is used in many areas of biotechnology.
- In agriculture, genes coding for traits such as frost, pest, or spoilage resistance can be genetically transformed into plants.
- In bioremediation, bacteria can be genetically transformed with genes enabling them to digest oil spills.
- In medicine, diseases caused by defective genes are beginning to be treated by Gene Therapy; that is, by genetically transforming a sick person’s cells with healthy copies of the defective gene that causes the disease.
The main purpose of the Bacterial Transformation is to introduce a foreign plasmid into a bacterium and to use this bacterium to amplify the plasmid in order to make large quantities of this.
Bacteria can acquire new genetic information by three means:
- Conjugation,
- Transduction and
- Transformation
During Conjugation, DNA is transferred directly from one organism to another, whereas in Transduction, the DNA is carried by Bacteriophages. And the Transformation includes insertion of naked DNA into bacterial cell with the help of different methods such as Electroporation and CaCl2 method etc.
But this Bacterial Transformation protocol should be done under aseptic environment so that no other bacterial genome can interfere with the genome of interest.
Maintenance of aseptic environment:
All culture vessels, media and instruments used in protocol must be sterilized. The importance is to keep the air surface and floor free of suspended particles and any other microorganisms. All operations are carried out in Laminar Air Flow, a sterile cabinet. Infection can be from
- The air contains a large quantity of suspended microorganisms in the form of fungal and Bacterial spores.
- The human body (a skin, breathe etc) carries several microorganisms.
Laminar Air Flow provides a work area with aseptic/sterile conditions. Laminar Air Flow has continuous displacement of air (it provides streamline flow of air) that passes through HEPA (High Efficiency Particulate Air) filter that removes the particulates from the air.
Laminar Air Flow are equipped with a UV lamp that should be turned on about 10-20 minutes before being used to sterilize the shell or cabinet or the surface of the Laminar Air Flow to avoid any kind of contaminations. Wipe down the surface with ethanol before and after each use.