Figure 1: (a) An example of 3D human skin models containing melanocytes (the hematoxylin and eosin (HE)-stained tissue image). SC, stratum corneum; BL, basal layer; SL, supporting layer; M, melanin. At the right side, a magnified schematic representation around the BL. KC, keratinocyte; MC, melanocyte. (b) The Raman spectroscopic system. (c) A schematic representation of the Raman measurements relative to the time course after stimulation. The rectangle represents the six-well-plate used to hold the cells; the open circle represents a piece of the skin model; the asterisk indicates the operation of picking a piece of the model skin out of the incubator. The label “(0)” on the vertical axis indicates when the H2O2 stimulations were applied to the three types of skin models.