Patent ID: 7220854

Claim:
A nucleotide having the formula wherein PM is a phosphate moiety, SM is a sugar moiety comprising a pentose sugar selected from a ribose or a deoxyribose, and BASE is a pyrimidine, purine or 7-deazapurine moiety, said PM being covalently attached to the C2′ or the C3′ or the C5′ position of SM, said BASE being covalently attached to the 1′ position of SM from the N 1 position when BASE is a pyrimidine or the N 9 position when BASE is a purine or 7-deazapurine, and said Sig is covalently attached to the C2′ or the C3′ or the C5′ position of SM directly or through a linkage group and Sig is a moiety which is detectable when said nucleotide is incorporated into a double-stranded nucleic acid duplex.