Tumor Cell Differentiation By Marker Free Fluorescence Microscopy

Autofluorescence and Raman spectra, images and decay kinetics of U251-MG glioblastoma cells prior and after activation of tumor suppressor genes are compared. While phase contrast images and fluorescence patterns of the tumor (control) cells and the less malignant cells are similar, differences can be deduced from autofluorescence spectra and decay times. In particular, upon excitation around 375nm, the fluorescence ratio of the protein bound and the free coenzyme NADH depends on the state of malignancy. Slight differences are also observed in Raman spectra of these cell lines, in particular at wave numbers around 970 cm(-1). While larger numbers of fluorescence and Raman spectra are evaluated by the method of multivariate data analysis, additional information is obtained from spectral images and fluorescence lifetime images (FLIM).