Estimating and correcting Mie scattering in synchrotron-based microscopic Fourier transform infrared spectra by extended multiplicative signal correction
Fiche publication
Date publication
mars 2008
Auteurs
Membres identifiés du Cancéropôle Est :
Pr SOCKALINGUM Ganesh
Tous les auteurs :
Kohler A, Sule-Suso J, Sockalingum GD, Tobin M, Bahrami F, Yang Y, Pijanka J, Dumas P, Cotte M, van Pittius DG, Parkes G, Martens H
Lien Pubmed
Résumé
We present an approach for estimating and correcting Mie scattering occurring in infrared spectra of single cells, at diffraction limited probe size, as in synchrotron based microscopy. The Mie scattering is modeled by extended multiplicative signal correction (EMSC) and subtracted from the vibrational absorption. Because the Mie scattering depends non-linearly on alpha, the product of the radius and the refractive index of the medium/sphere causing it, a new method was developed for estimating the Mie scattering by EMSC for unknown radius and refractive index of the Mie scatterer. The theoretically expected Mie contributions for a range of different alpha values were computed according to the formulae developed by Van de Hulst (1957). The many simulated spectra were then summarized by a six-dimensional subspace model by principal component analysis (PCA). This subspace model was used in EMSC to estimate and correct for Mie scattering, as well as other additive and multiplicative interference effects. The approach was applied to a set of Fourier transform infrared (FT-IR) absorbance spectra measured for individual lung cancer cells in order to remove unwanted interferences and to estimate ranges of important a values for each spectrum. The results indicate that several cell components may contribute to the Mie scattering.
Référence
Appl Spectrosc. 2008 Mar;62(3):259-66.