Figure 6.

Kinetics of PEI-mediated transfection. Perinatal rat sympathetic neurons were transfected with 1 μg LacZ plasmid and 5 μg PEI after five days in vitro. At various times following transfection (0.25, 1, 3, 5, 10, and 21 d) cells were fixed and assayed as to the presence of β-galactosidase using X-gal histochemistry. The % neurons expressing β-galactosidase (LacZ⁺) were determined by counting 500 cells per well and expressing the data points as mean % LacZ⁺ neurons of three separate wells ± SEM.