Patent ID: 7977057

Claim:
A method for determining the presence or absence of nucleic acid in a sample, wherein the method comprises: a) combining an unsymmetrical cyanine dye compound with a sample to prepare a labeling mixture, wherein the sample is immobilized on a solid or semi-solid support and the unsymmetrical cyanine dye compound has the formula wherein X is S or C(CH 3 ) 2 ; R 1 is a fused benzene, methoxy, a C 1 -C 6 alkyl; R 2 and R 3 are independently a C 1 -C 6 alkyl; R 4 is a C 1 -C 6 alkyl or a methoxy; t is independently 0, 1, 2, 3, or 4; s is independently 0, 1, 2, 3 or 4 and n is 0, 1, 2 or 3; b) incubating the labeling mixture for a sufficient amount of time for the unsymmetrical cyanine dye compound to associate with the nucleic acid to prepare an incubated sample; c) illuminating the incubated sample with an appropriate wavelength to prepare an illuminated sample; and d) observing the illuminated sample whereby the presence or absence of the nucleic acid is determined, wherein the unsymmetrical cyanine dye compound is combined with the sample before the sample is immobilized, and wherein the nucleic acid is a combination of DNA and RNA, with the proviso that the unsymmetrical cyanine dye compound is not thiazole orange when the support is a polymeric gel.