LABELLED NUCLEOTIDES
The invention provides a nucleotide or nucleoside having a base attached to a detectable label via a cleavable linker, characterised in that the cleavable linker contains a moiety selected from the group comprising: Formula (1) (wherein X is selected from the group comprising O, S, NH and NQ wherein Q is a C 1-10 substituted or unsubstituted alkyl group, Y is selected from the group comprising O, S, NH and N(allyl), T is hydrogen or a C 1-10 substituted or unsubstituted alkyl group and * indicates where the moiety is connected to the remainder of the nucleotide or nucleoside).
1 - 45 . (canceled)
46 . A method for determining the identity of a nucleotide in a target single-stranded polynucleotide, comprising:
(a) providing one or more of the nucleotide A, G, C and T or U in which each of said nucleotides has a base that is attached to a distinct detectable label via a linker, said linker being cleavable with a water-soluble phosphine; and a nascent polynucleotide complementary to the target polynucleotide, one of said provided nucleotides being suitable for incorporation into said nascent polynucleotide;
(b) incorporating the nucleotide suitable for incorporation into said nascent polynucleotide; and
(c) carrying out a method as defined in claim 45 .
47 . The method as claimed in claim 46 wherein steps (a) and (b) are repeated one or more times so as to determine the identity of a plurality of bases in the target polynucleotide.
48 . A method as claimed in claim 46 wherein step (a) comprises contacting the provided nucleotides with the target sequentially.
49 . A method as claimed in claim 46 wherein step (a) comprises at least one substep of providing one of the four said nucleotides.
50 . A method as claimed in claim 49 wherein step (a) further comprises, after, said substep, providing the other three nucleotides simultaneously or sequentially.
51 . A method as claimed in claim 50 wherein said other three nucleotides are added sequentially, either by providing them one at a time; or two simultaneously and then the remaining one; or one of the three and then the remaining two simultaneously.
52 . A method as claimed in claim 46 wherein step (a) comprises at least a substep of providing two of the four said nucleotides.
53 . A method as claimed in claim 52 wherein step (a) further comprises, after said substep, providing the other two nucleotides simultaneously or sequentially.
54 . A method as claimed in claim 46 wherein step (a) comprises at least a substep of providing three of the four said nucleotides.
55 . A method as claimed in claim 54 wherein step (a) further comprises, after said substep, providing the remaining nucleotide of the four said nucleotides.
56 . A method as claimed in claim 46 wherein step (a) comprises providing all four of the said nucleotides and contacting them with the target simultaneously.
57 . A method as claimed in claim 46 wherein any unincorporated nucleotides are removed prior to the provision of further nucleotide(s) and/or the effecting of step (c).
58 . A method as claimed in claim 57 wherein step (c) is effected without unsuitable nucleotides having been provided after provision of said suitable nucleotide.
59 - 60 . (canceled)