Figure 5. Representative cell images of plasmid DNA uptake, induced in a solution of low pH.

HaCaT cells were incubated in the presence of Cy3 tagged DNA plasmid (red), at either pH 7.4 or pH 5.0. Cell membrane is stained with alexa-488 (green) conjugated subunit B cholera toxin, and the nucleus is stained with DAPI (blue). (A) Cells incubated at pH 7.4, show very little presence of tagged plasmid. Bar size = 20 µm. (B) Cells incubated at pH 5.0, showing extensive presence of the plasmid in the cells. Bar size = 20 µm. (C) Higher magnification of cells incubated at pH 5.0. Bar size = 10 µm.