Transfection methods

There are multiple ways of introducing nucleic acids into mammalian cells and there is no method that works for all cell types. Therefore, many methods and reagents have been developed during the last years to facilitate the transfection of a broad range of cell lines. These methods can be separated into three main groups:

• Chemical methods. All these methods have the same principle: the addition of positively charged molecules which will form complexes along with the nucleic acid, allowing their interaction with the cell membrane and their subsequent cell entrance. The three main chemical methods are summarized in figure 1.

Figure 1. Chemical transfection methods. A. Lipid-based transfection, B. Calcium phosphate-based transfection, C. Cationic polymer-based transfection.

• Physical methods. These methods use diverse physical tools to deliver nucleic acids, electroporation being the most common one.

• Biological methods. These methods are commonly used in clinical research and they use viruses. This virus-mediated transfection is also known as transduction.