Change the media of the cells the previous day. add the plasmid (0.5ul of transposase plasmid: 0.5ug/ul) /(0.25ul of GFP plasmid:1ug/ul) to 50ul OptiMEM add 2.5yl Transfection reagent to 50ul of OptiMEM, incubate 5min mix plasmid and transfection reagent together add lipofectamin (1.5ul/3ul) to 50 ul of OptiMEM add the plasmid to Lipofectamin, incubate for 30min, add it drop by drop to the cells. media changed after 20h.