Patent ID: 7655409

Claim:
A method for detecting DNA in the presence of RNA, wherein the method comprises the steps: a. combining a nucleic acid reporter molecule with a sample to prepare a labeling mixture, wherein the nucleic acid reporter molecule has a DNA/RNA ratio of fluorescence enhancement greater than about one wherein the nucleic acid reporter molecule is according to the formula wherein W represents the atoms necessary to form one or two fused substituted 5- or 6-membered aromatic rings or one or two unsubstituted 5- or 6-membered aromatic rings; R 2 is a substituted alkyl, unsubstituted alkyl, substituted arylalkyl, unsubstituted arylalkyl, substituted heteroalkyl, unsubstituted heteroalkyl, alkoxy, carboxy, carboxyalkyl, hydroxy, hydroxyalkyl, sulfo, sulfoalkyl, amino, aminoalkyl, alkylamino, dialkylamino, or trialkylammonium; α is 0 or 1; n is 0 or 1; X is O, S, or Se; D is a substituted pyridinium, unsubstituted pyridinium, substituted quinolinium, or unsubstituted quinolinium moiety; with the proviso that the compound is substituted by at least one negatively charged moiety at a physiological pH; b. incubating the labeling mixture for a sufficient amount of time for the nucleic acid reporter molecule to associate with DNA in the sample to form an incubated mixture; c. illuminating the incubated mixture with an appropriate wavelength to form an illuminated mixture; and, d. observing the illuminated mixture whereby the DNA is detected in the presence of RNA.