Fig. 4

Discrimination in glioma cell lines. (A) Images representing the multicellular spheroids generated by the hanging drop method for the three cell lines, magnification 200X. (B) Images representing cells grown in 2D (monolayers) and 3D (spheroids) under the Raman confocal microscope after 48 h before acquisition. (C) 3D PCA plot of the individual cells (one dot represents one cell) grown in 2D using the three first PCs. (D) 3D PCA plot of all the individual spheroids using the three largest PCs. (E) Pair-wise comparison between the mean spectra of grade III and grade IV individual cells. (F) Pair-wise comparison between the mean spectra of grade III and grade IV spheroids. (G) Pair-wise comparison between the mean spectra of grade IV 2D and grade IV 3D cells. Circles drawn on PCA plot highlight trends assessed subjectively by eye