The present invention provides novel quencher composition comprising anthraquinone quencher moieties. The anthraquinone quencher moieties are useful as quencher labels when attached to biomolecules such as natural or modified polynucleotides, oligonucleotides, nucleosides, nucleotides, carbohydrates and peptides. For example, polynucleotides can be labeled at the 3' terminus with fluorescence quencher solid support compositions, and polynucleotides can be labeled at internally or at the 5' terminus. The detectable probes may have a format like molecular beacons, scorpion probes, sunrise probes, conformationally assisted probes and TaqMan probes.