Raman microspectrometry will be used to measure basis spectra from various skin constituents. In this technique, Raman spectra are measured from freshly frozen tissue samples that are sliced into thin sections as is done in histology. A microscope system is used to focus the excitation laser beam to a small spot of approximately 2 mm in diameter on the sample, and a Raman spectrometer measures the emitted Raman spectrum. In this way, Raman spectra of individual microscopic tissue components can be isolated. These individual component spectra will be determined for keratin, cell nuclei, collagen, cytoplasm, melanin, water, sebaceous glands, etc.