Transfection of siRNA can result in off-target effects, in which siRNAs affect the expression of non-homologous or partially homologous gene targets. Off-target effects, which may produce misleading results in RNAi experiments, can be largely avoided by using low siRNA concentrations. Using HiPerFect Transfection Reagent, highly efficient transfection and silencing have been observed, in some cases with as little as 10 pM siRNA. HiPerFect Transfection Reagent provides highly efficient siRNA transfection over a range of siRNA concentrations from low to high, allowing researchers to choose the siRNA concentration they wish to use. It can be used to transfect a wide range of cell types, including HeLa, HeLa S3, HEK 293, NIH/3T3, Huh-7, HepG2, MCF-7, HUVEC, and NHLF (see figure "Efficient transfection of NHEK").
microRNAs (miRNAs) are a class of endogenous small RNA molecules with similar characteristics to siRNAs. miRNAs play a role in many diverse biological processes such as development, differentiation, and apoptosis. Transfection of synthetic miRNA mimics or inhibitors is a technique used to elucidate the targets and roles of particular miRNAs. miRNA mimics are chemically synthesized miRNAs which mimic naturally ocurring miRNAs upon transfection into the cell. miRNA inhibitors are single-stranded modified RNAs which specifically inhibit miRNA function. Reduced gene expression after transfection of an miRNA mimic, or increased expression after transfection of an miRNA inhibitor, provide evidence that the targeted miRNA is involved in regulation of that gene. Alternatively, the role of miRNAs in various pathways can be studied by examination of a specific phenotype after transfection of an miRNA mimic or inhibitor. HiPerFect Transfection Reagent was developed for highly efficient transfection of eukaryotic cells with siRNA, and is ideally suited to transfection of miRNA mimics or inhibitors.