Figure 2.

Comparison of 4 and 24 h transfection efficiency in MDA-MB-435 cells. MDA-MB-435 cells were transfected with DOTAP (2:1), Lipofectamine (4:1), H³K4b (4:1) and H²K4b (4:1) in complex with the PCI-Luc. For the 4 h transfection, the complex was incubated in Opti-MEM without serum for 4 h, the cells were washed, and DMEM containing 10% FCS was added; after 24 h, luciferase activity was measured. For the 24 h transfection experiments, the complex was added directly to the wells containing the 10% FCS DMEM and cells; after 24 h, luciferase activity was measured as described in Materials and Methods. *, P < 0.001; H²K4b (24 h) versus H²K4b (4 h); DOTAP (4 h) versus DOTAP (24 h); Lipofectamine (4 h) versus Lipofectamine (24 h); t-test.