Infrared and Raman imaging spectroscopy of ex vivo skin.

This primer describes and illustrates experimental protocols for both Fourier transform infrared (FTIR) spectroscopic imaging and confocal Raman mapping of ex vivo skin and thereby acquaints the reader with these measurement techniques, including the temporal and spatial limitations associated with each technique. The experimental conditions by which the unique 'molecular histology' information obtained from confocal Raman mapping and infrared spectroscopic mapping of ex vivo skin is generated will be described. Raman and FTIR spectra of tissue, when collected in spatially resolved arrays, permit the generation of 'molecular images' of tissue components and tissue organization without the use of fluorescent labels or chemical stains. To illustrate the molecular information from ex vivo skin that can be spectroscopically imaged with confocal Raman and infrared microspectroscopy, we have collected new data using both techniques and generated spectral images which illustrate the capacity of each technique to provide unique insights into skin histology, biochemistry and biophysics. Understanding the measurement possibilities and specific constraints of both approaches is a prerequisite to their meaningful use as powerful research tools in skin research.