Patent ID: 7998706

Claim:
A method of extending a polynucleotide comprising forming a hybridization complex between a 3′-extendable polynucleotide and a complementary sequence in a template polynucleotide, and extending the 3′-extendable polynucleotide in the presence of at least one labeled nucleotide 5′-triphosphate and a template-dependent nucleic acid polymerase under conditions effective to append at least one labeled nucleotide to the 3′-end of the extendable polynucleotide, wherein said at least one labeled nucleotide 5′-triphosphate comprises a labeled nucleotide 5′-triphosphate having the structure wherein X is a bond or a linker having from 1-50 atoms, wherein the atoms are selected from C, H, N, O, S, P and Si, LABEL is at least one detectable label, W 1 taken alone is —H or —OH, W 2 is —OH or a non-extendable moiety selected from the group consisting of —H, azido, amino, fluoro, chloro, and methoxy, W 3 when taken alone is —H or when taken together with W 1 is —CH 2 —O—, and W 4 is triphosphoryl; and wherein said extending is performed in the presence of said labeled nucleotide 5′-triphosphate and four different alternate nucleotide triphosphates, selected from ATP, GTP, UTP, and CTP to extend an RNA chain or selected from dATP, dGTP, dCTP and dTTP to extend a DNA chain.