In order to facilitate genetic studies in mammalian cells, we developed a cost efficient lipid-mediated plasmid DNA transfection protocol utilizing food oil as a transfer-mediator. The intention was to create and/or improve a cheap and efficient method. Compared to the conventional transfection using commercially available lipofection-specimen, this procedure remarkably enhanced the delivery of a GFP reporter plasmid into HEK293 cells. Our technique of gene delivery is adaptable for large scale production since the costs of the reagent is two to three orders of magnitude cheaper than conventional commercial available reagents.