Transfection

Transfection is a powerful analytical molecular biology tool in which molecules such as DNA, RNA, proteins and oligonucleotides are specifically introduced into the recipient cell and integrate into the chromosomal DNA of the recipient cell, causing a change in the cell's characteristics.

The following methods of transfection are widely used:

• Calcium phosphate method: It is a widely used method to introduce foreign DNA plasmids into cells. The method was first described by Graham and Van der Ebb in 1973. The calcium phosphate transfection technique involves the precipitation of DNA and calcium phosphate, allowing the formation of small complexes that are internalized into a cell and eventually transfected.
• Electroporation: A method in which an electric current is applied across the cell membrane of a given cell, resulting in the formation of a temporary pore. This "pore" aids in the transfer of exogenous materials from the medium into the cytoplasm or nucleus, thus transfecting the cell. Among the advantages of electroporation is its versatility, as it is effective on almost all different types of cells.
• Viral transfection: The viral method uses viral vectors to introduce nucleic acids into cells. The different types of viral vectors that can be used include retroviruses such as human immunodeficiency virus (HIV) and murine leukemia virus (MuLV), and DNA viruses such as herpes simplex virus (HSV), adenovirus, and adeno-associated virus (AAV).
• Lipofection: Lipofection is the method in which a lipid (usually cationic) is used to incorporate the nucleic acid into the cell, the genetic material is transferred into the cell using liposomes. Cationic lipids form vesicles in aqueous solution with a lipid bilayer called liposomes. When liposomes encounter nucleic acids, they reform into nucleic acid-lipid complexes called lipoplexes, which can be actively taken up by eukaryotic cells by endocytosis. In this case, the lipoplex enters the cytosol of the cell via the endosomes. The advantages of lipofection include high efficiency, ability to transfect different types of nucleic acid into a variety of cell types, reproducibility, ease of handling and application.

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