Fluorescent microscopy images of cells after being transfected.

Transfection alters the genetic makeup of eukaryotic cells by introducing foreign nucleic acids, including DNA, RNA, and small noncoding RNAs such as siRNA, shRNA, and miRNA. Scientists use transfection techniques to advance cellular research and enhance drug discovery by enabling researchers to characterize cellular processes and study molecular disease mechanisms.1–3 

Planning a Successful Transfection

Researchers deliver transfected nucleic acids as oligonucleotides or in a viral or plasmid vector, which carries the genetic material into the host cells. Transfection can be stable or transient. Stable transfection results in sustained, long-term expression, whereas expression will eventually be lost after transient transfection as host cells replicate. Scientists apply stable transfection for long-term and large-scale genetic and pharmacology studies. Transient transfection is useful for short-term studies, such as investigating the effects of gene knock-in or knock-down.2 

When planning transfection experiments, researchers must first select a delivery method to transfer nucleic acids into target cells. The delivery method may be physical, such as electroporation, or chemical involving lipid-based or nonlipid-based reagents. Delivery methods affect the host cell surface and facilitate nucleic acid entry into the cell. In the case of chemical delivery methods, the reagent forms a complex with the nucleic acid to enhance contact with the cell membrane. The ability to successfully transfect a cell varies by cell type, protocol, and composition of the transfection reagent.1,2

Transfection Challenges

Four blue containers of X-tremeGENE™ transfection reagents from Roche®.

Transfection often causes cytotoxicity due to the effects of transfection reagents on the cell surface, which can stress the cells. Additionally, transfection reagents can be expensive and have highly specific applications, so researchers often need to buy different reagents depending on the nucleic acids and cell types they transfect. When choosing transfection reagents, researchers must identify the cell type and culture conditions for their experiment. Rare cell cultures such as neurons or primary cells require reagents that facilitate nucleic acid delivery in hard-to-transfect cells. Researchers must also consider the amount of reagent they will need before selecting an appropriate transfection reagent, as this will affect cost and toxicity. The ideal product will minimize the number of different reagents a researcher needs and optimize the effectiveness of their experiments. Therefore, an ideal reagent has multiple applications, low cytotoxicity, and high transfection efficiency.1–3

X-tremeGENE™ transfection reagents from Roche® efficiently transfect many types of cells, from common to rare and primary cells. Scientists can choose from a range of X-tremeGENE™ transfection reagents based on their experimental needs, to deliver a variety of molecules in different applications, including lentiviral production, gene knock-down, and gene-editing.1,4–7 

An All-In-One Solution

Researchers looking for an all-in-one reagent to use across different experiments can choose the new X-tremeGENE™ 360 transfection reagent, a high-performing, versatile, and reliable solution for delivering a variety of nucleic acids into many different cell types. This innovative reagent forms a complex with DNA or RNA and can transfect siRNA/miRNA, plasmid DNA, and CRISPR/Cas9 materials into animal or insect cells with high efficiency. It is a universal polymer designed for a broad range of eukaryotic cells, including many cell lines not transfected well by other reagents. The X-tremeGENE™ 360 reagent functions well in the presence or absence of serum and researchers can use it for transient transfection, stable transfection, siRNA expression, and CRISPR gene editing. Finally, the X-tremeGENE™ 360 reagent is cost and time effective. 1 mL of X-tremeGENE™ 360 transfection reagent can be used to perform up to 10,000 transfections in 96-well plates. Because it produces minimal cytotoxicity and cell morphology changes when adequate numbers of cells are transfected, it eliminates the need to change media after adding the transfection reagent, saving time and media expenses.1,6 This universal and effective transfection reagent with minimal cytotoxicity is an attractive solution for researchers seeking to optimize their transfection protocols and declutter their cell culture room freezers. 


  1. “X-tremeGENE™ Transfection Reagents Comparison Guide,” https://www.sigmaaldrich.com/CA/en/technical-documents/technical-article/genomics/advanced-gene-editing/general-recommendation-for-transfection-reagent-selection, accessed on September 4, 2022. 
  2. Z.X. Chong et al., “Transfection types, methods and strategies, a technical review,” PeerJ, 9:1-37, 2021.
  3. “Introduction to Cell Transfection,” https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/cell-culture-and-cell-culture-analysis/transfection-and-gene-editing/transfection-reagents, accessed on September 4, 2022.
  4. “Lentiviral Production Using X-tremeGENE HP Transfection Reagent,” https://www.sigmaaldrich.com/US/en/technical-documents/protocol/cell-culture-and-cell-culture-analysis/transfection-and-gene-editing/xtghp-lenti-protocol, accessed on September 4, 2022.
  5. “X-tremeGENE™ HP DNA Transfection Reagent,” https://www.sigmaaldrich.com/US/en/product/roche/xtghpro, accessed on September 4, 2022.
  6. “X-tremeGENE™ 360 Transfection Reagent,” https://www.sigmaaldrich.com/US/en/product/roche/xtg360ro, accessed on September 4, 2022.
  7. “X-tremeGENE™ 9 DNA Transfection Reagent,” https://www.sigmaaldrich.com/US/en/product/roche/xtg9ro, accessed on September 4, 2022.