Applications of Micro-Raman Imaging in Biomedical Research

Abstract

Recent results are presented of the application of imaging micro-Raman spectrometers in cellular biophysics and biomedical research. Various micro-Raman spectrometers have been developed that are now routinely applied in these fields. Results are presented that were obtained with a linescan Raman microspectrometer and with a Raman imaging microscope. Applications of Raman linescan spectrometry concern the investigation of polytene chromosomes obtained from the salivary gland of Chironomus thummi thummi. The distribution of DNA and proteins was investigated in bands and interbands. In a second example of Raman linescan spectrometry, bone implants were investigated. These bone implants were coated with thin layers of materials that improve biocompatibility. The density, crystallinity and protein distribution can be investigated. Information from Raman imaging may help in selecting the proper materials for maximum biocompatibility. Raman imaging microscopy is used whenever two-dimensional spatial information is required on the distribution of molecules or molecular components. Raman images are presented of filipine and phenylalanine in human eye-lenses in and around radial shades. Raman imaging is a particularly important tool for the study of the distribution of non-fluorescent drugs inside living cells. This is illustrated for the non-fluorescent drug cobalt octacarboxyphthalocyanine.