An analysis of DNA cytophotometry on tissue sections in a rat liver model.

Since the nuclear DNA content of neoplastic cells may be of predictive value, it is important that a reliable approach to cytophotometric DNA estimation in tissue sections be available by which cases can be assessed retrospectively and correlated with a recorded clinical course. Studies on a rat liver model indicate that the additional problems involved in using sections can be overcome. Selection of an appropriate section thickness has shown that spindle-shaped nuclei can be used reliably as an internal control for a test population with spherical nuclei. The location of higher ploidy peaks may then be predicted once the diploid absorbance has been found.