[Quantitative and qualitative aspects of Feulgen's reaction in neurons of Gasser's ganglion of the rat fetus].

This quantitative and qualitative photometric study of the Feulgen reaction, shows in trigeminal ganglion neurones of rat foetuses, a differential effect of the tested fixatives upon chromatin stability in response to different types of acid hydrolysis. The technic conditions the most adapted to foetal ganglion neurones are: fixation with formalin (Regaud or salted formalin), hydrolysis with chlorhydric acid (HCl 5N) at room temperature which gives a Feulgen reaction of great intensity and stability for hydrolysis lasting from 30--40 to 60 minutes. Furthermore the fact that the maximal reaction intensity is reached with relatively short hydrolysis points out the weakness of chromatin stability in foetal ganglion neurones. Histophotometric study of the Feulgen reaction conditions in rat foetal trigeminel ganglion neurones.