Dicationic perylene dye for precipitation and quantitation of DNA

The novel dicationic dye N,N'-bis3,3'-(dimethylamino)propylamine!-3,4,9,10-perylenetetracarboxylic diimide (DAPER) is prepared by reacting 3,4,9,10-perylenetetracarboxylic dianhydride with N,N-dimethylaminopropylamine. The dye DAPER is particularly useful in a rapid, sensitive method for the precipitation, recovery and quantitation of DNA from solutions containing DNA, which method involves the steps of (a) adding the dye DAPER to a solution containing DNA and allowing the resulting mixture to equilibrate; (b) collecting the resulting precipitate; (c) removing weakly bound DAPER from the precipitate; (d) extracting DAPER therefrom by the addition of a solvent therefor; and (e) determining the amount of DNA precipitated by measuring either the absorbance or fluorescence of DAPER in the solvent extract from step (d).