fig2

Figure 2. A set of typical resonance Raman raw spectra collected from a horizontal section of normal human skin sample, and a vertically sliced BCC skin sample measured at different depths. (Top), the spectrum was from dermis layer of normal skin showing nine feature peaks; (middle), the spectrum was from the vertically sliced BCC sample at a depth of 100 µm. There are eight characteristic peaks including increased peaks at 753 cm^-1 and 1,589 cm^-1, but intense carotenoids peaks at 1,161 cm^-1 and 1,521 cm^-1 disappeared compared to the normal tissue (top); (bottom), the spectrum was from BCC sample at a depth of 1,100 µm, substantially similar to the depth of 100 µm, with six Raman peaks, but carotenoids peaks at 1,161 cm^-1 and 1,521 cm^-1 are present and obviously weaker than normal tissue sample (top). Those peaks of 753 cm^-1 and 1,589 cm^-1 greatly decreased in comparison with the depth of 100 µm. BCC: basal cell carcinoma