ISOLATION OF POLYMERASE-NUCLEIC ACID COMPLEXES AND LOADING ONTO SUBSTRATES

摘要

Compositions, methods and systems are provided for the isolation of polymerase-nucleic acid complexes. Complexes can be separated from free enzyme by using hook molecules to target single stranded regions on the nucleic acid. Active complexes can be isolated from mixtures having both active and inactive complexes by initiating nucleic acid synthesis so as to open up a portion of a double stranded region rendering that region single stranded. Hook molecules are targeted to bind the sequences that are thus exposed. The hook molecules bound to active polymerase-nucleic acid complex are isolated, and the active polymerase-nucleic acid complexes released. Also disclosed are compositions, devices, and methods for loading molecules-of-interest onto a substrate by contacting beads having molecules-of-interest attached to them with the substrate, for example by providing a field that brings the beads into proximity or contact with the substrate and moves the beads with respect to the substrate. Such molecules-of-interest can be deposited onto substrates for single-molecule analysis.