Detection of DNA in agarose gels using berberine and Mordant Yellow 3R

A nontoxic and simple staining method for the detection of DNA in agarose g els is described. After eletrophoretic separation, the gels were stained wi th 5 mu g/ml of berberine (BB) prepared in distilled water and then the gel s were soaked in 20 mu g/ml of aqueous Mordant Yellow 3R (MY3R) solution. E mployment of MY3R as a counterion dye efficiently quenched unwanted backgro und fluorescence of BE. This method can detect as little as 10 ng of plasma membrane H+-ATPase cDNA obtained from Arabidopsis thaliana L. (AHA1, 3.2 k b) under a long wavelength of UV irradiation (366 nm) within 1 h. (C) 1999 Academic Press.