We started with human embryonic kidney (HEK) 293T cells, a widely used immortalized cell line, in a conventional 2D culture with DMEM supplemented by 10 vol% FBS and the two antibiotics penicillin and streptomycin. The cells were cultured at 37 °C with 5 vol% CO2 and the origami-coding molecular program (scaffold + staples) was directly added to the outer medium of the cultured cells (Figs. ).