Distribution of acridine orange-stained RNA in neuroblastoma cells during differentiation.

Vital staining of neuroblastoma cells with acridine orange produces a bright intracellular red-orange fluorescence most probably due to the occurrence of RNA. The distribution of this fluorescence depends on the state of morphological differentiation. The fluorescence is predominantly found in the perikaryon, the growth cones, and the endings of the processes of differentiated cells. This is of special interest in respect to the biochemistry of differentiation and the function of nerve cells. Comparative autoradiographical studies with 3H-uridine demonstrate that the newly synthesised RNA is transported into the endings of the cell processes.