What recommendations do you have for selecting a transfection reagent?
• What is the stability of transfection reagents? Invitrogen’s transfection reagents are shipped on wet ice and should be stored at 4 °C. Invitrogen guarantees the performance of the product, if stored and handled properly, for six months following purchase. We do not recommend freezing transfection reagents as this usually decreases transfection performance. All tubes are labeled with an expiration date that is two years after date of manufacture. • Is cell density (% confluence) and passage number important considerations? Yes. Cell density will affect transfection performance. For example, Lipofectamine™ 2000 provides excellent transfection performance at a confluence of 90% or greater, while slight toxicity may be observed at confluencies lower than this. We recommend using Optifect™ for cell densities <70% confluence. Passage number may affect transfection experiments. We recommend splitting and plating cells consistently. Excessive numbers of passages may decrease transfection pe
