Cationic lipid-mediated transfection is one of the most popular methods for introducing foreign genetic material into cells. Although first generation of lipid-based transfection reagents relied on artificial liposomes that could envelop nucleic acids and then fuse with the cell membrane to deposit their cargo inside (Fraley et al., 1980), newer cationic lipid-based reagents spontaneously form condensed nucleic acid-cationic lipid reagent complexes via electrostatic interactions between the negatively charged nucleic acid and the positively charged head group of the synthetic lipid reagent. These complexes are believed to be taken up by the cell through endocytosis and then released in the cytoplasm. Once in the cell, transfected DNA is translocated to the nucleus to be expressed by a yet unknown mechanism, while RNA or antisense oligonucleotides skip the translocation step and remain in the cytoplasm (see Cationic Lipid-Mediated Transfection).

The advantages of cationic lipid-mediated transfection are the ability to transfect a broad range of cell lines with high efficiency, its applicability to high-throughput screens, and the ability to deliver DNA of all sizes, as well as RNA and proteins. In addition, this method can be applied to both stable and transient expression, and unlike other chemical methods, it can be used for in vivotransfer of DNA and RNA to animals and humans. The main drawback of cationic lipid-mediated transfection is the dependence of transfection efficiency on the cell type and culture conditions, requiring the optimization of transfection conditions for each cell type and transfection reagent (see Considerations for Cationic Lipid-Mediated Transfection).

Life Technologies™ offers a wide range of cationic lipid-mediated transfection reagents for efficiently introducing DNA, RNA, siRNA, or oligonucleotides into a broad range of cell types, including the Lipofectamine® 3000 reagent. The Lipofectamine® 3000 reagent leverages the most advanced lipid nanoparticle technology to enable superior transfection efficiency and reproducible results in a broad spectrum of difficult-to transfect cell types with improved viability. For more information on selecting the appropriate transfection reagent for your application, see Cationic lipid transfection reagents.

Dilute RNA, siRNA, or oligonucleotides and the transfection reagent in separate tubes.

Combine nucleic acid and transfetion reagent to form complexes. Positive charge on cationic lipid helps binds to phosphare backbone on nucleic acid.

Add nucleic-transfection reagent complexes to cells. Positive charge on cationic lipid helps bind complex to membrane.

Complexes enter the cell via endocytosis.

Assay transfected cells for gene expression or silencing.

Cationic lipid mediated delivery workflow.