Hot hydrochloric acid hydrolysis and UV Feulgen staining of rat liver sections fixed in CRAF and CRAF-like fixative.

Sections of rat liver fixed in CRAF III and Nawaschin's fixative in Dutt's modification were subjected to hydrolysis in 1N HCl at 60 degrees C for different periods of time and to Schiff's staining according to the UV Feulgen technique. The study showed that Feulgen reaction intensity depends upon time of hydrolysis, optimum coloration being possible only after 10-15 min of hydrolysis. Prolongation of hydrolysis beyond this time produced decreased staining intensity which is retained for further 35 min of hydrolysis thus forming a plateau. Further prolongation of hydrolysis results in gradual deterioration of the staining intensity which culminates in utterly pale coloration of the nuclei after one hour's hydrolysis. A possible explanation for this phenomena is suggested.