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Short answer
Lipofection is transfection with cationic lipid reagents. The reagent spontaneously forms complexes with nucleic acid, the positively charged complex attaches to the cell surface, and the cell takes it in by endocytosis. Thermo Fisher describes it as one of the most popular transfection methods, able to deliver DNA, RNA or protein. Electron microscopy work on two cationic lipids found two different routes of endosomal escape, so the lipid chemistry matters.
Definition and scope
Lipofection (also called cationic lipid transfection or lipid-mediated transfection) is a chemical, non-viral way of getting a nucleic acid into cultured cells. The term describes the delivery chemistry, not a single product: any cationic lipid transfection reagent used to form nucleic acid-lipid complexes is lipofection. The broader question of which delivery method suits which experiment, including the biosafety review that applies to it, is covered in transfection methods, controls and biosafety. This page stays on the lipid method itself.
How lipofection works
Thermo Fisher’s Gibco gene delivery reference gives the sequence in plain terms:
- The reagents spontaneously form nucleic acid-cationic lipid complexes when mixed with the payload.
- The positive surface charge of the complex lets it attach to the cell surface.
- The complex is then internalised by endocytosis.
- For DNA, the payload must still reach the nucleus for transcription. For mRNA, translation can happen in the cytoplasm.
What happens after endocytosis
Le Bihan and colleagues labelled plasmid DNA with aminated nanoparticles and followed it by transmission electron microscopy in cell lines, using two cationic lipids, BGTC and DOSP (Nucleic Acids Research 39(4):1595-1609, 2011). They observed morphological changes of the lipoplexes, membrane reorganisations and endosomal membrane ruptures on the way to endosomal escape.
The two lipids did not behave the same way. With BGTC, the DNA partly or completely dissociated from the lipid before endosomal escape. With DOSP, lipoplexes remained visible within ruptured vesicles, which the authors read as a more direct route for DNA release and endosome escape. They suggest the two pathways could explain the lipids’ different transfection efficiencies. That is the main reason not to treat lipofection as one uniform mechanism: the lipid in the reagent shapes how the cargo gets out.
Types and related concepts
Transfection reagent
A transfection reagent is the commercial formulation used for the delivery step. Cationic lipid reagents are one class of them, and Thermo Fisher lists reagents for DNA, RNA or protein delivery. Other classes of delivery, such as electroporation and viral vectors, work on different principles.
Transfection protocol
People searching for a transfection protocol usually want the reagent manufacturer’s instructions for their specific product and cell line, which differ by product and are the authority for amounts and timings. Optimisation and troubleshooting principles that apply across methods are in the CASRAI transfection guide.
Related delivery methods
For non-chemical alternatives see electroporation parameters and cell-type optimisation and what an electroporator is. For stable, long-term expression through viral delivery, see the lentiviral transduction guide.
Where it matters for labs: choosing lipofection
Thermo Fisher states that the ideal technique should be selected based on cell type and experimental needs. Its comparison of gene delivery technologies rates cationic lipids as follows, which gives a sourced checklist:
- Easy-to-transfect cells: rated +++ (highest).
- Hard-to-transfect cells (primary and stem cells): rated ++.
- Cell viability: rated +++.
- Payloads larger than 7 kb: rated ++, against +++ for electroporation.
- Payload type: DNA, RNA or protein.
In practice this means lipofection is a sensible starting point for adherent, easy-to-transfect lines when viability matters, while a large construct or a hard-to-transfect primary cell type is a reason to compare it against electroporation. For lab managers, the reagent is a recurring consumable tied to the payload type and cell lines in use, so those two facts, rather than the reagent name, are what to settle first when planning cell culture supplies. Work with recombinant nucleic acids also falls under institutional biosafety review, covered in the linked CASRAI guide.
Common misunderstandings
- Lipofection is only for plasmid DNA. The reagents are available for DNA, RNA or protein delivery.
- All lipofection reagents release cargo the same way. In the electron microscopy study of BGTC and DOSP, BGTC lipoplexes dissociated from DNA before endosomal escape while DOSP lipoplexes stayed visible within ruptured vesicles.
- Lipofection works equally well in every cell. The vendor’s own rating drops from +++ in easy-to-transfect cells to ++ in hard-to-transfect ones.
FAQ
What is the difference between lipofection and transfection?
Transfection is the general term for introducing nucleic acid into cells by non-viral means. Lipofection is one way of doing it, using cationic lipids.
Is a transfection reagent the same as lipofection?
Not always. A transfection reagent is any formulation used to deliver the payload. Cationic lipid reagents are lipofection reagents, but other reagent chemistries and physical methods such as electroporation also exist.
Can lipofection deliver RNA as well as DNA?
Yes. Thermo Fisher lists reagents for DNA, RNA or protein delivery. DNA must reach the nucleus for transcription, whereas mRNA can be translated in the cytoplasm.
Where do I find a lipofection protocol?
Use the instructions supplied with the specific reagent and the biosafety approval for your work. This guide covers how the method works and when to choose it, not product-specific amounts or timings.
Sources
- Thermo Fisher Scientific, Gibco Cell Culture Basics, “Gene delivery technologies”: https://www.thermofisher.com/us/en/home/references/gibco-cell-culture-basics/transfection-basics/gene-delivery-technologies.html (date checked 2026-10-29).
- Le Bihan O, et al. “Probing the in vitro mechanism of action of cationic lipid/DNA lipoplexes at a nanometric scale.” Nucleic Acids Research 39(4):1595-1609 (2011): https://doi.org/10.1093/nar/gkq921 (date checked 2026-10-29).
