Figure 2: The skin models containing Black type melanocytes (a) without and with the stimulation of the hydrogen peroxide (the hematoxylin and eosin (HE)-stained tissue images). A single piece of the Black type skin model was stimulated by 10 μL of H2O2 (10 mM). (b) The corresponding absorbance values at 405 nm. The error bars correspond to the standard deviation values. The thicknesses of the skin models are approximately from 250 to 300 μm.