Transfection of exogenous DNA into eukaryotic cells has become a common technique. There are a number of different products available to perform transfections, yet the efficiency of molecule delivery into the cell varies with each transfection protocol and is often cell-line dependent. Those who have experienced low or variable transfection efficiencies in their experiments should consider using the Qiagen Superfect Transfection Reagent. The reagent is an activated, spherical dendrimer that possesses radiating branches with charged amino groups at its ends, enabling them to compact negatively-charged DNA. The compact nature increases the likelihood of its uptake into the cell. Overall, this Superfect-DNA complex is positively-charged, permitting it to bind to negatively-charged receptors on the cell’s surface for subsequent uptake.
The Superfect transfection procedure is very easy to perform and involves little hands-on time. Incubation times with Superfect-DNA complexes can be as short as 2 hours (and may be even shorter if using primary cells). Also, because the transfection efficiency is typically high, very little DNA is needed. One can use this reagent for both transient and stable transfections and for both adherent and suspension cells.
Because I work with cell lines that are difficult to transfect with the calcium phosphate co-precipitation method, I have used the Superfect reagent extensively. The popularity of this reagent has allowed Qiagen to offer tips for optimization for a broad range of cell lines. These tips can be found in the manual or on the Qiagen website.
There are some points worth considering before you start using the reagent. The most important is that the Superfect reagent can be cytotoxic. This may be cell-line dependent and cytotoxicity may be circumvented by tweaking the ratio of Superfect:DNA or the cell’s exposure time to the reagent. From my own experiences, shortening the time of exposure helps.
Overall, I would highly recommend the Superfect Transfection Reagent. The protocol is simple and fast (the entire procedure can take only a couple of hours). And because it is widely used, it is likely that the finer procedural details have already been optimized for your cell lines.
Joe Lau, Ph.D.
Immunobiology Center
Mount Sinai School of Medicine