Figure 4.

Plot of the first two principal component scores for (A) for the full spectrum (100 ${\mathrm{cm}}^{-1}$–4300 ${\mathrm{cm}}^{-1}$) and (B) the conventional fingerprint (400 ${\mathrm{cm}}^{-1}$–1800 ${\mathrm{cm}}^{-1}$). Both plots show good separation between the healthy controls and the malignant tissue samples (both tonsil squamous cell carcinoma and squamous cell carcinoma). The numbers in parentheses represent the information content associated with each principal component.