Gene transfer effect of mimovirus in vitro. Mimoviruses were prepared by mixing 3 μg of plasmid pIL-12, respectively, with peptide [K]18S12 at various peptide/DNA charge ratios in 50 μl of HBS. P815 cells were incubated with the mimoviruses or controls for 6 h in a 24-well plate. The control group includes three negative controls—no DNA (naked P815 cell), naked pIL-12, and pTCAE (pT) mixed with DOTAP—and a positive control: pIL-12 mixed with DOTAP. The medium was then replaced by 1 ml of supplemented medium, and the incubation was continued for a total of 48 h before the supernatants were harvested to detect the level of IL-12 by ELISA. The results of one of three similar experiments are shown here.