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).
本发明提供了一种核苷酸或核苷,其碱基通过可断裂的连接剂连接到可检测标记上,其特征在于可断裂的连接剂包含从以下群组中选择的基团:公式(1)(其中X从包括O,S,NH和NQ的群组中选择,其中Q是C1-10取代或未取代的烷基,Y从包括O,S,NH和N(
丙烯基)的群组中选择,T是氢或C1-10取代或未取代的烷基,*表示基团连接到核苷酸或核苷的其余部分的位置)。