Biomedical Applications of Infrared and Raman Microscopy

INTRODUCTION The desire to analyze smaller and smaller amounts of material is a common goal as we push the limits of technology in trying to solve chemical and biochemical problems. In gas chromatography, fused-silica capillary columns (0.25 mm) have almost completely replaced larger-bore (1/4 and 1/8-inch) packed columns [1], and as detection limits are reduced in liquid chromatography, microbore columns with inner diameters of 1 mm or less are quickly replacing the more traditional 4-mm columns [2]. Capillary electrophoresis is likewise demonstrating advantages over conventional gel electrophoresis for many applications [3]. Mass spectrometers are now capable of detecting and identifying materials in the picogram to femtogram range [4]. Vibrational spectroscopic measurements which are the subject of this review currently utilize the experience of optical microscopists in configuring instrumentation to analyze extremely small specimens.