KI67 EXPRESSION IN RAT NORMAL ORAL EPITHELIUM IN RELATION TO DIFFERENT TIME OF FIXATION IN 10% NEUTRAL BUFFERED FORMALIN

In many clinical disorders and cancers, immunohistochemistry (IHC) is employed extensively for diagnosis and prognosis. This study was conducted to evaluate the impact of fixation time on Ki67 immunohistochemical expression in rat oral tissues biopsies. 20 albino Rats were employed. The palatal oral mucosa, both soft and hard, was dissected and preserved for one day and seven days in 10% neutral buffered formalin. A Ki67 immunohistochemical staining procedure was used. The findings were statistically analyzed using SPSS after the percentages of positively stained nuclei were graded. Using 10% NBF, there were no significant differences in Ki67 expression between the soft and hard palatal epithelium of rat oral cavity after one day or seven days of fixation. However, there were significant differences between the soft and hard palate specimens after one day and seven days of fixation. As a conclusion , the fixation time within 1 to 7 days has no effect on Ki67 staining of both studied oral sites. On the other hand, Ki67 expression is slightly higher in hard palate epithelium than soft palate regardless of the fixation time