Fig. 1.

Transfected DNA rapidly kills Drosophila S2 cells. The viability of S2 cells was measured by MTT cleavage at 1 h after electroporation, unless otherwise stated. a DNA-dependent cell death of S2 cells after electroporation with 10 µg of CT DNA. The bars represent data from 40 experiments (mean ± SEM) normalised to the no-DNA sample for each experiment. **** p < 10⁻¹⁵. b Dose-dependent response of S2 cells after transfection with the indicated amounts of CT DNA. A representative of 2 experiments is shown, with error bars showing the range of results for duplicate electroporations. c DNA-specific response of S2 cells. Cells were electroporated with 10 µg of CT DNA that was untreated or treated with DNase I. The bars represent data from 3 experiments (mean ± SEM), normalised to the no-DNA sample for each experiment. d S2 cells are not killed by synthetic dsRNA poly(I:C). S2 cells were electroporated with 10 µg of CT DNA or poly(I:C), and cleavage of MTT was measured after 1 and 3 h. The bars represent data from 3 experiments (mean ± SEM), normalised to the no-DNA samples. e Mouse BMM responses to DNA and dsRNA transfection. BMMs were electroporated as per panel d. Data are from a representative experiment and error bars show the range of duplicate electroporations. f DNA-dependent cytotoxic effect in S2 cells after transfection with Lipofectamine 2000. Cells in 100 µl were transfected with 2 µg of CT DNA or poly(I:C), with 4 µl of transfection reagent or 4 µl of transfection reagent alone (mock). Cleavage of MTT was measured at 18 h after transfection. Data are from 5 experiments (mean ± SEM), normalised to the mock sample (** p = 0.013).