Page 181 - Vibrational Spectroscopic Imaging for Biomedical Applications

CHAPTER 6

Widefield Raman Imaging

of Cells and Tissues

Shona Stewart, Janice Panza, Amy Drauch

ChemImage Corporation, Pittsburgh, Pennsylvania, USA

6.1 Introduction
Raman spectroscopy is an analytical tool commonly utilized in
research and industrial laboratories of many disciplines. That the
Raman scattering phenomenon is highly selective and requires lit-
tle sample preparation makes it a very promising option for ana-
lytical needs. For industries involving high Raman scatterers, such
as pharmaceutical and polymer materials, Raman methodologies
are routine. Recently there has been a move for many analytical
technologies to progress to the imaging paradigm. Images, conve-
nient to convey and comprehend, are becoming more in demand
by both practitioners and clients. Chemical images contain, in addi-
tion to morphological information, data that describes the molecu-
lar composition of a sample. Raman imaging combines Raman
spectroscopy with digital imaging technology in order to visualize
material chemical composition and molecular structure. There are
a variety of ways to generate a Raman image from dispersive spec-
tra; however, these have their own limitations. Widefield Raman
imaging provides spectral information of all pixels of an entire
field of view at once and thus can be considered to be a more ideal
mode of acquisition. This chapter describes widefield Raman imag-
ing, the technological issues involved in the acquisition and pre-
processing of data, and the methods that can be employed to
analyze the large datasets that result from such experiments. The
chapter also describes the state of the technology with respect to
the study of cells and tissues.

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