Fig. 2

Radio-resistant cells possess distinct morphological and Raman spectral features. a Transmission electron microscopy images of P and RR show nuclear (left panel) and mitochondrial morphology (right panel and zoomed images). Yellow arrows point towards observed changes. b Raman spectra (650–1750 cm^− 1) of P (gray) and RR (black). Altered spectral features are highlighted at 751, 1265 and 1576 cm^− 1 by red arrows. A total of 30 spectra analyzed for P and RR are depicted in the confusion matrix as a box indicating spectral matching between P and RR. Boxes in green depict matched spectra and blue depicts unmatched spectra. Parental MCF7 is denoted as “P” and radioresistant cell line is denoted as “RR” and a.u. is arbitrary units. Images were taken at magnification × 1000 and scale bar depicts 2 μm for cellular and nuclear morphology and 1 μm for mitochondrial morphology, respectively