The CCK-8 method was used to examine cell cytotoxicity and proliferation ability. We prepared cell suspension counts, inoculated them into 96-well plates, and put them back in the cell incubator to wait for cells to adhere. In accordance with the experiment group, different kinds of plasmid were transfected into U87 and U251 cells, maintaining a total volume of 100 μL. 10 μL of CCK-8 was added and incubated for 1–2 h. The wavelength of the plate reader was selected at 450 nm to determine the optical density (OD) value.
