Energy dependence of DNA-mediated gene transfer and expression

When cells are transfected with calcium phosphate-precipitated DNA, most of the DNA is internalized through active endocytosis but a small pool is postulated to be internalized by passive diffusion. The relative importance of these two DNA pools in gene transfer and expression has never been examined. We now show that mouse Ltk− fibroblasts internalize >90% of radioactively labeled, calcium phosphate-precipitated DNA by a temperature- and …