Tagged multi-nucleotides useful for nucleic acid sequencing

A method for determining the sequence of a nucleic acid comprising:

• (a) providing a nanopore sequencing composition comprising:
• a membrane, an electrode on the cis side and the trans side of the membrane, a nanopore with its pore extending through the membrane, an electrolyte solution in contact with both electrodes, an active polymerase situated adjacent to the nanopore, and a primer strand complexed with the polymerase;
• (b) contacting the nanopore sequencing composition with (i) a strand of the nucleic acid;
• and (ii) a set of compounds each comprising a single tag covalently linked to a plurality of nucleoside-5′-oligophosphate moieties, wherein the tag is a molecular moiety capable of producing a detectable signal, each nucleoside-5′-oligophosphate moiety is capable of being a substrate for a polymerase, and each member of the set of compounds has a different tag that produces a different detectable signal when the tag is situated in a nanopore;
• and
• (c) detecting the different detectable signals of the tags over time and correlating to each of the different tags the different compounds incorporated by the polymerase which are complementary to the nucleic acid sequence, and thereby determining the nucleic acid sequence.