BEWARE OF CONNECTIVE-TISSUE PROTEINS - ASSIGNMENT AND IMPLICATIONS OFCOLLAGEN ABSORPTIONS IN INFRARED-SPECTRA OF HUMAN TISSUES

Infrared spectra of human central nervous system tissue and human brea st carcinoma are presented. The spectra are discussed in terms of the composition of the tissues. It is shown that differences between spect ra of white and grey matter can be rationalised on the basis of differ ences in lipid content. Spectra of the choroid plexus and arachnoid vi llus of the meninges show a series of absorptions not observed in othe r CNS tissue. These absorptions are discussed in terms of the connecti ve tissue content of the samples. We demonstrate that the presence of collagen results in the appearance of a series of characteristic absor ptions which may be mis-assigned as DNA phosphate absorptions. The imp lications of the presence of collagen in tissues for the diagnosis of disease states by IR spectroscopic methods, with particular reference to cancer, is discussed.