Raman and Infrared Microspectral Imaging of Mitotic Cells

Abstract

We report the first ever Raman and infrared microspectroscopic images of human cells at different stages of mitosis. These spectroscopic methods monitor the distribution of condensed nuclear chromatin, and other biochemical components, utilizing inherent protein and DNA spectral markers, and, therefore, do not require the use of any stains. In conjunction with previously reported data from the G1, S, and G2 phases of the cell cycle, the complete cell division cycle has now been mapped by spectroscopic methods. Although the results reported here do not offer new insights into the distribution of biochemical components during mitosis, the recognition of cell division without the use of stains, and the possibility of doing so on living cells, may be useful for an automatic, spectroscopic determination of the proliferation rates of cells and tissues. Spectral images were constructed by plotting spectral intensities of DNA or protein versus the coordinates from which spectra were recorded. We found that both Raman and infrared intensities depend on the overall chromatin density variation among the individual subphases of mitosis.

Chapter 10 Infrared and Raman Microscopy in Cell Biology

“…The chromosomal condensation during metaphase and anaphase, shown in the second and third rows, respectively, is manifested by a large intensity increase of the DNA-related peaks (Matthäus et al, 2006). The bottom row of images in Fig.…”

“…Mitotic cells were selected by microscopic inspection of fixed cells grown on a substrate in culture (Matthäus et al, 2006). The spectral maps reported below for different stages of mitosis do not represent a time course of mitosis of one individual cell, but time points in mitosis of several different cells.…”

Molecular pathology via IR and Raman spectral imaging

“…The last section presented here introduces another aspect of spectroscopic imaging technology that was developed during the past few years [34,35]. This method uses Raman micro-spectroscopy of cells, in a way similar to that described in Section 4.5, but at a much higher spatial resolution.…”

“…This results in images which can differentiate the individual cellular components such as the membrane, the cytoplasm, the nucleus and nucleoli, membrane-rich structures in the cytoplasm, mitochondria, etc. [34][35][36]. This method can be viewed as a label-free analog of confocal fluorescence microspectroscopy, and can produce images with similarly high spatial resolution.…”

Spectroscopic and chemometric approaches to radiobiological analyses

“…Quantitative spectral changes attributable to the biochemical processes occurring during cell culture and mitosis [32,33], proliferation [34], differentiation, [35,36], adhesion [37], death [38][39][40][41][42], and invasion [43] have previously been observed with FTIRM and CRM. The increased resolution in CRM imaging has also been exploited to enable the detection of cellular mitochondrial distribution [44] and phagosomes [45].…”