DNA Transfection Mediated by Lipofection Protocol Protocol should be viewed as a starting point for systematic optimization of transfection mediated by lipofecting agents. Once a positive signal has been obtained from a transfected plasmid carrying a standard reporter gene, optimal conditions for transfection can be established by systematic variation of parameters such as the initial cell density, the amount and purity of DNA, the media and serum, and the time of exposure of the cells to the cationic-lipid-DNA complex.
DNA Transfection Using Polybrene Protocol Polybrene and DMSO can be used to achieve stable transformation of several types of cells by plasmid DNA. The yield of transformants is up to 15-fold greater with Polybrene than with calcium phosphate-DNA coprecipitation. However, there is no difference between the two methods in the efficiency of transformation of cells by high-molecular-weight DNA.
Optimizing Electrotransfection of Mammalian Cells In Vitro Protocol Protocol describes transfection of plasmid DNA into mammalian cell lines using electroporation, a process whereby external application of electric pulses induce cell membrane permeability. Cells in suspension and small volume cells are difficult to transfect, whereas adherent cells and large volume cells are relatively easy. Regardless of cell size or phenotype, transfection efficiency increases with a high concentration of cells in a small volume.
Transfecting and Plating RAW 264.7 Cells with Lipofectamine 2000 Protocol The following procedure is for simultaneous transfection and plating of RAW 264.7 cells. This protocol results in approximately 50% to 70% cell viability, and of those viable cells, 20% to 40% are transfected when using pEYFP-N1
from Clontech. Include: Procedure for Splitting Cells before Transfection; Procedure for Preparing Lipofectamine 2000 and DNA; Preparation of RAW 264.7 Cells for Transfection.
Transfection Mediated by DEAE-Dextran: High-efficiency Method Protocol DEAE-dextran is generally used to obtain a burst of transient expression of cloned genes after transfection of mammalian cells. Many variants of the technique have been described, all of which seek to maximize the uptake of DNA and to minimize the cytotoxic effects of DEAE-dextran. In this protocol cells are exposed briefly to a high concentration of DEAE-dextran-DNA and then to chloroquine diphosphate, which is a facilitator of transfection.
Transfection of Mammalian Cells with siRNA Duplexes Protocol Protocol describes a method for the delivery of siRNAs into mammalian cells in the absence of reporter plasmids. This is best achieved with transfection reagents developed for the delivery of antisense oligodeoxynucleotides. The quantities of reagents given below are calculated for the transfection of one well of a 24-well plate.