Fig. 4: PCA score plots analysis results on the dataset of cell-averaged Raman spectra measured in living human cancer lines.

By screening the first PCs through MLR, PCA score plots can be used to linearly separate human colon cancer cell types in the PCA space, based on their biochemistry. Sample size = 5 independent cells/phenotype. a The scatter matrix compares pair-wise the first 7 PCs, explaining 96% of the total dataset variance. Red dashed lines highlight pairs of the most significant PCs, namely, PC5 and PC7. Grey dashed lines identify the less significant PC, namely, PC2. b The entire set of significant PCs is represented in the 3D PCA space.