Patent ID: 7452674

Claim:
A method for detecting the presence or absence of a target nucleic acid in a test sample, comprising: a) contacting the test sample with a composition comprising an oligo- or poly nucleotide probe wherein the oligo- or polynucleotide probe comprises a detectable label of formula: base is wherein sugar is covalently bonded to N 1 of the base; wherein R 1 is —NHC(O)NH 2 ; wherein R 2 is —H or alkyl; each of X, Y, and Z is independently —H, —OH, —O-alkyl, —SH, —SR 4 , —NHR 4 , —NR 4 R 5 , wherein R 3 is H or metal; R 4 is —H or alkyl; R 5 is —H or alkyl; linker is (CH 2 CH 2 O) n CH 2 CH 2 , (CH 2 CH 2 O) n , (CH 2 O) n or (CH 2 ) n ; wherein n is an integer from 1 to 30; Q is O, S, or NH; label is a colorimetric, chemiluminescent, bioluminescent, a fluorescent compound, or a non- or weakly fluorescent compound; wherein the oligonucleotide probe is capable of selectively or specifically hybridizing with the target nucleic acid under conditions of moderate stringency; optionally exposing the sample to light of said excitable wavelength; and b) detecting whether said contacting produces a change in color or fluorescence emission of the composition; such that a change in color or fluorescence emission of the composition indicates that the target nucleic acid is present in the test sample.