RESUMEN
Fluorescent staining method is a sensitive cytochemical staining method, it can reflect minimal changes of biochemical components of cells. The 7690-Xu fluorescent staining solution prepared with thioflavine can show the heterogeneo- us fluorescence of cells in different stages of differentiation. The younger cells with low degree of differentiation show blue fluorescence, the lower the degree the deeper the color. Along with the differentiation of cells, the blue color of fluorescence deflects to the red color of spectrum gradually, the blue color of fluorescence of cytoplasm changes gradually to bluish, bluish-green, and finally yellow color. The blue color of fluorescence of nucleus changes through greyish- blue to orangeyellow or orange-red.The cytoplasm of cells in various organs with high degree of differentiation appears yellow, and the nucleus orange-yellow or orange-red in color.