Nucleic acid probe and nucleic acid sequencing method

A nucleic acid probe combination, which comprises 4 groups of nucleic acid probes, wherein each group of nucleic acid probes contains a nucleic acid probe, wherein the nucleic acid probe comprises a first moiety, a second moiety, a linker and a detectable label, wherein:

• the first moiety has a base of A, T, U, C or G,
• the second moiety has random bases and/or universal bases, and the number of the bases is 3 or more,
• the first moiety is ligated to the second moiety via the linker, and the ligation between the first moiety and the linker can be cleaved,
• the detectable label is ligated to the second moiety or the linker;
• and
• the linker does not contain a sulfur atom;
• wherein:
• the first group of nucleic acid probes:
• comprising the nucleic acid probe of which the base of the first moiety is A;
• the second group of nucleic acid probes:
• comprising the nucleic acid probe of which the base of the first moiety is T or U;
• the third group of nucleic acid probes:
• comprising the nucleic acid probes of which the base of the first moiety is C;
• the fourth group of nucleic acid probes:
• comprising the nucleic acid probes of which the base of the first moiety is G;
• and the detectable labels in the 4 groups of nucleic acid probes are different from each other;
• the 4 groups of nucleic acid probes are mixed or not mixed;
• the mole number of the first group of nucleic acid probes and that of the fourth group of nucleic acid probes are equal;
• the mole number of the second group of nucleic acid probes and that of the third group of nucleic acid probes are equal;
• the sum of the mole number of the first group of nucleic acid probes and that of the fourth group of nucleic acid probes is less than or equal to the sum of the mole number of the second group of nucleic acid probes and that of the third group of nucleic acid probes;
• and
• the molar ratio of the first group of nucleic acid probes:the second group of nucleic acid probes:the third group of nucleic acid probes:the fourth group of nucleic acid probes is (0.5-2):(3-5):(3-5):(0.5-2);
• more preferably 1:4:4:1.