Plasmid DNAs directly injected into mouse brain with lipofectin can be incorporated and expressed by brain cells.

In this study, we demonstrated that lipofectin-treated DNAs which were injected into mouse brain could be incorporated and expressed by brain cells. When L7RH-beta gal plasmid DNA harboring E. coli beta-galactosidase gene fused with the nuclear location signal of SV40 T-antigen gene was injected into brains of 1-week-old mice, cells whose nuclei appeared to be densely stained with the chromogenic substrate X-gal were detected in several portions of the brain till 9 days after injection. Injection of pMLV-CAT plasmid DNA which contains the E. coli chloramphenicol acetyltransferase (CAT) gene also resulted in cells immunoreactive to the anti-CAT antibody.