Transfection is the process of introducing exogenous genetic material in the form of DNA or RNA into eukaryotic cells. The entry of this genetic material into the cell is allowed by the transient opening of pores in the membranes, it is then possible to introduce a plasmid, a small interfering RNA or other. Cells manipulated to accept a foreign nucleic acid are called competent cells. Transfection is not to be confused with transduction, which uses a different route of entry into the cell (through the use of a viral vector).
There are different methods of transfection, which are different chemical and/or physical treatments that will make the plasma membrane more permeable. The main methods used are :
- Precipitation with calcium phosphate: the DNA will adhere to the membrane and enter the cell.
- Lipofection, which will allow the DNA to be associated with cationic lipids, will create liposomes that will enter the cell by endocytosis.
- Electroporation, which uses an electrical pulse to depolarize the membrane and open the pores.