Cell Transfection@zoonbio

Introduction

Transfection is a special technique to transfer exogenous gene into cells. With the development of gene and protein function research, transfection has become a basic method often involved in laboratory work. Transfection can be divided into three types: physical mediated, chemical mediated and biological mediated.

The ideal cell transfection method should have the advantages of high transfection efficiency and low cytotoxicity. Virus mediated transfection is the most efficient method and has the advantage of low cytotoxicity. However, the preparation procedure of virus transfection method is complex and often has strong selectivity to cell type, which is difficult to popularize in general laboratory. Other physical and chemical mediated transfection methods have their own characteristics.

It should be pointed out that no matter which transfection technology is used, in order to obtain the optimal transfection results, the transfection conditions may need to be optimized. There are many factors affecting the transfection efficiency, from cell type, cell culture conditions and cell growth status to the operation details of transfection methods.

Common Transfection Methods

1.Liposome transfection

Cationic liposomes are positively charged on the surface. They can bind DNA molecules to form DNA- liposome complexes by electrostatic interaction with phosphate radicals of nucleic acids. They can also be absorbed by negatively charged cell membranes and then enter cells through fusion or endocytosis. Liposome transfection is suitable for transfecting DNA into suspension or adherent culture cells. It is one of the most convenient transfection methods in the laboratory. Its transfection efficiency is higher than that of calcium phosphate method. Because of the toxicity of liposomes to cells, the transfection time is usually less than 24 hours.

2.Electroporation transfection

The current can break down the cell membrane reversibly to form transient water channels or pores on the membrane to promote DNA molecules to enter the cell. This method is called electroporation transfection. When the transfection efficiency of some liposomes is very low or the transfection is almost impossible, electroporation is recommended. Generally, high electric field intensity can kill 50% - 70% of cells.Now, in view of the fact that electroporation transfection can cause a large number of cell death, we have developed a kind of electroporation protective agent, which can greatly reduce the cell death rate and improve the efficiency of electroporation transfection.

3.Viral infection

For the cell lines that can not be transfected successfully by liposome transfection or electroporation transfection, virus infection is recommended. This method can rapidly infect 100% and the detection success rate is high.

4.Calcium phosphate transfection

Calcium phosphate precipitation is a method of transfection of DNA into eukaryotic cells based on calcium phosphate DNA complex. Calcium phosphate is considered to be beneficial to promote the binding of exogenous DNA to the surface of target cells.The calcium phosphate DNA complex adheres to the cell membrane and enters the target cell through pinocytosis. The transfected DNA can be integrated into the chromosome of the target cell to produce stable clones with different genotypes and phenotypes. It can be widely used to transfect many different types of cells, not only suitable for transient expression, but also can generate stable transformation products.