(A) Electrophoretic analysis of the ssDNA products. Lane1 is ssDNA isolated with silica column from the culture of JM109/pGEM5Z(+)-EGFP/M13KO7 complex. Lane2 is ssDNA isolated from M13KO7-infected JM109/pGEM5Z(+)-EGFP culture with the conventional method. Lanes 3 and 4 are the same ssDNA samples as Lanes 1 and 2, respectively, after treatment with DSN. (B) Fluorescent images of HCT116 cells co-transfected with ssDNA and pDsRed1-N1. ssDNA (3 μg) isolated from JM109/pGEM5Z(+)-EGFP/M13KO7 complex was treated with or without DSN, and then co-transfected with pDsRed1-N1 (1 μg) into HCT116 cells with Lipofectamine 2000 (Invitrogen, Carlsbad, CA). The representative green and red fluorescent images were taken 24 hr later. Co-transfection with pDsRed1-N1 was used to ascertain that the transfection efficiencies were comparable.