Compound for sequencing by synthesis
The present invention provides deoxynucleoside tri- or tetraphosphate comprising a 3′ nitrate and a detectable label covalently bound to the oxygen atom of an oxymethyl or oxyallyl or oxypropargyl substitution of a nucleobase. Such compounds provide new possibilities for future Sequencing by Synthesis technologies.
1. A method for analyzing a DNA sequence comprising the steps of
a) providing a nucleic acid template with a primer hybridized to said template forming a primer/template hybridization complex,
b) adding DNA polymerase, and at least one labeled deoxynucleoside tri- or tetraphosphate comprising a 3′-nitrate and a detectable label covalently bound to the oxygen atom of an oxymethyl or oxyallyl or oxypropargyl substitution of a nucleobase, and a pyrophosphatase,
c) subjecting said reaction mixture to conditions which enable a DNA polymerase catalyzed primer extension reaction,
d) determining, whether said compound has been incorporated into said primer/template hybridization complex,
e) simultaneously removing the 3′-nitrate group and optionally said label from said complex by means of adding a sulfide or a mercaptane, and
f) repeating steps b) to e) at least once.
2. The method according to claim 1 , wherein a different labeled deoxynucleoside tri- or tetraphosphate compound is added during repeat of step b).
3. The method according to claim 1 , wherein a mixture of 4 differently labeled deoxynucleoside tri- or tetraphosphate compounds representing A, G, C and T/U are used in step b).