Our aim is to make a quantitative evaluation of glycogen possible on sernithin sections of hepatic tissue, epon embedded and prepared for an ultrastructural study that is not limited to glycogen aspects only.
The work has been done on Salmo gairdneri. On each liver both a biochemical estimate and histophotometric measurements are performed. For the histophotometric study, the tissue is fixed with 4% paraformaldehyde in 0, 15 M sodium cacodylate buffer (pH 7.3) ans postfixed with osmium tetroxyde. The 1μ sections are stained with P.A.S. in well defined conditions. A counterstaining with Erlich's hematoxylin can be performed for a later morphological study. As for the ultrastructural study, thin sections are either contrasted with uranyl acetate and lead citrate or undergo a silver proteinate treatment.
For the biochemical study, KOH digestion of the liver is done and the alcohol precipitated glycogen is estimated with anthrone reagent. There is a good agreement between the results of the histophotometric method and those of the biochemical estimates.
The validity of these methods is then discussed.