The interactions between berberine and ethidium bromide with DNA

The spectroscopy interactions between berberine and DNA,ethidium bromide and DNA are studied by UV-absorption,fluorescence,circular dichroism spectroscopy and agarose gel electrophoresis methods.When DNA exists,the fluorescence intensity of berberine and EB have a great increase,but the change of pH value has not great effect on the wavelength and intensity of the fluorescence.The absorbance of UV spectra present a hypochromic effect with DNA concentration increasing.The CD spectra of DNA has a great change both in negative and positive spectra.In the agarose gel electrophoresis,the luminescence intensity of EB-DNA system is more sensitive than berberine-DNA system.In the quantitative determination of DNA,the berberine rather than EB is implored,which can offer an important base of new reagent in the determination of DNA,and also afford clue to search more sensitive probe of DNA.