An automated two-dye flow injection analysis system to quantitate DNA and RNA in crude extracts of tissues is described. The method uses the fluorochrome dyes ethidium bromide and Hoechst 33258. DNA concentration is determined directly from its fluorescence in Hoechst dye. RNA is estimated from fluorescence in ethidium bromide after subtraction of the fluorescence due to DNA. This method has several advantages: a simple extraction procedure, a low detection limit (0.01 micrograms DNA and 0.10 micrograms RNA), automation, and a high sample throughput.
Animals Autoanalysis