Infrared micro-spectroscopy of human cells: Causes for the spectral variance of oral mucosa (buccal) cells

Abstract

We discuss the causes contributing to the variance of the spectra of individual human epithelial cells. This aspect has largely been ignored in previous studies, but needs to be understood for diagnostic applications of infrared micro-spectroscopy. We attribute the spectral variance to Mie scattering, and to variations of nuclear contributions to the overall spectra caused by different nuclear size.

Spectroscopic and chemometric approaches to radiobiological analyses

“…Various cytological sample preparation techniques exist that often involve the centrifugal deposition of cells onto spectroscopic mounting substrates [62], or their culture in-situ on the substrate. Cell culture on such substrates has been demonstrated to be toxic to the cell, although use of molecular biochemical coatings (such as gelatin) have been shown to ameliorate such effects [37].…”

“…Spectra may, due to optical transmission effects exhibit a broad oscillating baseline that is attributable to Mie scattering [62,65]. This effect arises since the nucleus and subcellular organelles may act as non-absorbing dielectric spheres and scatter, in a wavelength and organelle-size dependent manner, the incident IR radiation.…”

“…frequency greater than 0.9, where a frequency of 1 is equivalent to that feature being selected on each of the independent runs of the GA) one consistent range over which the features are selected is between ~ 2600 cm -1 to 1850 cm -1 , another being from 3720 cm -1 to 3500 cm -1 , which do not contain features of biochemical origin, but rather may be assigned to changes in the optical characteristics of the cell [62,65] due to organelle swelling that occurs during the cell cycle, and during apoptotic and necrotic cell death.…”

Molecular and chemical characterization by Fourier transform infrared spectroscopy of human breast cancer cells with estrogen receptor expressed and not expressed

“…It is able to detect changes in the chemical composition of intact cells, making it useful for spotting differences in cell populations: for example, to tell the difference between normal and tumoral cells [3,20,23,25]. The absorption spectrum in the infrared spectral range provides information regarding the identification of the covalent bonds of a molecule mainly, but additional information about molecular conformation and intermolecular interactions can be extracted from the spectrum [12,17,[27][28][29].…”

Rapid and label‐free classification of human glioma cells by infrared spectroscopic imaging

“…The vast volume of spectral data generated from imaging permits sophisticated multivariate statistical analysis of data and provides a wealth of molecular information (29,30). Several excellent reports are available that characterized the application of infrared spectroscopic imaging for the discrimination of various cell types such as tumor cells of the skin (31) oral mucosa cells (32) and even B and T cells in human spleen (33). In this contribution, we demonstrate the potential of infrared spectroscopic imaging to classify human glioma cells.…”