Reagents for reversibly terminating primer extension

Abstract

This invention relates to the field of nucleic acid chemistry, more specifically to the field of compositions of matter that comprise triphosphates of modified 2'-deoxynucleosides and oligonucleotides that are formed when these are appended to the 3′-end of a primer, wherein said modifications comprise NHmoiety attached to their 3′-hydroxyl group and a fluorescent species in a form of a tag affixed to the nucleobase via a linker that can be cleaved. Such compositions and their associated processes enable and improve the sequencing of oligonucleotides using a strategy of cyclic reversible termination, as outlined in U.S. Pat. No. 6,664,079. Most specifically, the invention concerns compositions of matter that are 5′-triphosphates of ribo- and 2′-deoxyribonucleosides carrying detectable tags and oligonucleotides that might be derived from them. The invention also concerns processes wherein a DNA polymerase, RNA polymerase, or reverse transcriptase synthesizes said oligonucleotides via addition of said triphosphates to a primer.