Fig. 4.

The peak area were semi-quantitative to compare differences of the specific Raman bands a 480 ${\mathrm{cm}}^{-1}$ (glycogen), b 831 ${\mathrm{cm}}^{-1}$ (tyrosine), c 840–860 ${\mathit{cm}}^{-1}$(polysaccharide structure), d 1003 ${\mathrm{cm}}^{-1}$ (phenylalanine), e 1080 ${\mathrm{cm}}^{-1}$ (amide II, typical phospholipid), f 1172 ${\mathrm{cm}}^{-1}$ (C–H in-plane bending mode of tyrosine), g 1206 ${\mathrm{cm}}^{-1}$ (hydroxyproline, tyrosine), h 1265 ${\mathrm{cm}}^{-1}$ (α-helix, collagen, tryptophan), i 1300 ${\mathrm{cm}}^{-1}$ (lipids), j 1337 ${\mathrm{cm}}^{-1}$ (amide III), k 1440 ${\mathrm{cm}}^{-1}$ (lipids), l 1658 ${\mathrm{cm}}^{-1}$ (amide I), m 1744 ${\mathrm{cm}}^{-1}$ (carbonyl feature of lipid spectra) in PHH (Lot:005), ProliHHs P1 and P4. The results represent median, ns p $\ge$ 0.05, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001 (PHH: primary human hepatocytes, ProliHHs: proliferating human hepatocytes, P1: passage 1, P4: passage 4)