Infrared spectroscopy of human cells and tissue. Part VII: FT-IR microspectroscopy of DNase- and RNase-treated normal, cirrhotic, and neoplastic liver tissue

In our efforts to understand the infrared spectral features of cells and tissues, and the spectral changes occurring between normal and disease states, we reported previously a detailed correlation between histochemical/immunohistochemical and spectral results. These results suggested an increase of nucleic acid spectral contributions in neoplastic, as compared to normal, tissue samples. In the present paper, these studies are extended to report the spectral features of DNA and RNA separately in these tissue samples. This was accomplished by selectively digesting either DNA or RNA from tissue sections, leaving behind the protein matrix with nuclear/cytoplasmic RNA or the protein matrix with nuclear DNA, respectively. These results demonstrate that the spectral changes between normal and neoplastic tissue are mostly due to an enhanced signature of DNA in neoplastic tissue. This enhancement is sufficiently Large to suggest that it is most likely due to an increased detectability of DNA, rather than an increase in concentration.