Single-Cell Raman Spectroscopy and Morphological Changes of Normal and Cancer Cells in Suspension

Spatially resolved spectroscopies provide a non-destructive in-situ probe at the single cell level. We employ micro-Raman spectroscopy to investigate the biochemical and structural composition of P69 and PC3 prostate cells. P69 is a non-tumorigenic cell line developed from normal prostate epithelial cells while PC3 is a highly aggressive metastatic prostate cancer cell line developed from bone metatasis. The studies were conducted to differentiate between benign and malignant cancer tissues. Micro-Raman spectra were measured with 633 nm excitation with less than 4 mW power on live cells both in suspension and on substrates. The Raman spectra reveal differences between normal and cancer cells in the C-C, amide I and amide III regions. We also investigate mechanical properties and morphological changes in individual cells employing high pressure microscopy. Our setup allows real time imaging of individual cells at variable pressure. We probe differences in cell mobility and mechanical stability between normal and cancer cells during a pressure cycle over the range from 0.1 to 200 MPa.