Figure 4.

Trypan blue staining. Optical microscopic images of the CT-26 cells treated with a PSi/EtOH:PEG solution (0.7 g/L) followed by NIR laser treatments (for 20 min at 600 mW/cm²) 4 times for 2 min each time with a time interval of 2 min. The cells were stained using trypan blue dye after the NIR laser treatments to examine cell damage. The cells indicated by arrows are some examples of dead cells turned blue after staining.