Effects of aphidicolin and α-amanitin on visualization of acridine orange binding to DNA in rat astrocytoma C6 cells

The purpose of this study was to examine effects of aphidicolin and α-amanitin on visuali- zation of acridine orange (AO) binding to DNA in rat astrocytoma C6 cells and to discuss briefly the significance of AO chromatin interaction products. Aphidicolin inhibited DNA synthesis but percentage of AO positive cells was approximately 60% of that of the untreated control cells, α-amanitin caused a slight inhibition of RNA synthesis and 3H- uridine incorporation in the treated cells was about 64% of that of the untreated cells, whereas a distinct decrease of the number of AO positive cell nuclei was observed. The results suggest that activity of RNA polymerase II and mRNA synthesis is mainly con- cerned in visualization of AO chromatin interaction products.