Methods of detecting fluorescence with anthraquinone quencher dyes

A method of detecting a target nucleic acid sequence in a sample by fluorescence, comprising:

• contacting the sample with an oligonucleotide specific for hybridizing to the target sequence labeled with a fluorophore and a quencher, wherein the quencher is an α-aminoanthraquinone, and wherein fluorescence of the fluorophore is reduced by fluorescence resonance energy transfer to the quencher or by ground state quenching by the quencher when the oligonucleotide is not hybridized to the target nucleic acid sequence;
• and
• detecting the presence of the target nucleic acid sequence in the sample by an increase in fluorescence from reduction of fluorescence resonance energy transfer to the quencher or from reduction of ground state quenching by the quencher upon hybridization of the oligonucleotide to the target nucleic acid sequence, or upon hybridization of the oligonucleotide to the target sequence and subsequent cleavage of the oligonucleotide.