FIG. 4.

Cytolytic activity of different concentrations of chlorhexidine on Chinese hamster corneal epithelial cells (HCORN). HCORN cells were incubated with medium, vehicle (1:4 dilution of 10% methanol) with or without different concentrations of chlorhexidine. The cytopathic effect assay was performed 8 hr later. After incubation, the plates were washed 3 times with the culture medium and stained with Giemsa stain. The remaining contents were solubilized in 200 μL of 5% sodium dodecyl sulfate in phosphate buffered saline and transferred to a new 96-well plate, and the density of the residual epithelial cells was quantified by determining the optical density at 590 nm on a microplate reader.*Significantly different from untreated controls (P<0.05).