Comparison of different commercially available cationic lipid-based transfection kits

Cationic lipid-containing nonviral vectors for intracellular DNA delivery (lipoplexes) are becoming an important tool in a number of applications in life sciences, biotechnology, agriculture, and medicine. They became a biotechnology industry product on their own, being marketed as transfection kits. Their number on the market, now exceeding 50, is growing steadily. Life science researchers could face a problem having such a large choice of products. In such a situation, a straightforward comparison of existing transfection kits is useful. Therefore, several new proprietary transfection kits (Effectene, FuGENE 6, GeneSHUTTLE-20, GeneSHUTTLE-40, and GenePORTER Transfection Reagents), as well as well-established ones of known composition (Lipofectin, LipofectAmine, DOSPER, and DOTAP Transfection Reagents) were chosen for simultaneous comparison of their in vitro activity and shelf stability. Using expression of human growth hormone in NIH 3T3 cells, it was shown that most of the kits show roughly the same order of magnitude of transfection, with FuGENE 6 and GeneSHUTTLE-40 being somewhat better. In parallel, stability tests were performed to assess the degree of lipid hydrolysis in different kits. It was shown that in all kits, level of non-esterified fatty acids increased upon storage at 4°C in aqueous dispersion, suggesting base-catalyzed hydrolysis of the ester lipids. The pattern of degradation was also clearly visible when lipid kit components were analyzed on TLC plates.