Application of a novel fluorescence probe in the determination of nucleic acids.

A novel fluorimetric method has been developed for rapid determination of DNA and RNA with hypocrellin A (HA) as a fluorescence probe, based on the fluorescence enhancement of HA in the presence of DNA or RNA. Maximum fluorescence is produced in the pH range 3.4-4.0, with maximum excitation and emission wavelengths at 470 and 600 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0-200.0 ng cm-3 for calf thymus DNA and 13.0-200.0 ng cm-3 for yeast RNA, respectively. The corresponding detection limits are 5.0 ng cm-3 for calf thymus DNA and 13.0 ng cm-3 for yeast RNA. The relative standard deviation of six replicate measurements is 4.5% for 100 ng cm-3 calf thymus DNA. DNA could be determined in the presence of 20% m/m yeast RNA. The mechanism for the binding of HA to DNA is also studied.