Organized Arrays of Individual DNA Molecules Tethered to Supported Lipid Bilayers

Abstract

An unappreciated aspect of many single-molecule techniques is the need for an inert surface to which individual molecules can be anchored without compromising their biological integrity. Here, we present new methods for tethering large DNA molecules to the surface of a microfluidic sample chamber that has been rendered inert by the deposition of a supported lipid bilayer. These methods take advantage of the "bio-friendly" environment provided by zwitterionic lipids, but still allow the DNA molecules to be anchored at fixed positions on the surface. We also demonstrate a new method for constructing parallel arrays of individual DNA molecules assembled at defined positions on a bilayer-coated, fused silica surface. By using total internal reflection fluorescence microscopy to visualize the arrays, it is possible to simultaneously monitor hundreds of aligned DNA molecules within a single field-of-view. These molecular arrays will significantly increase the throughput capacity of single-molecule, fluorescence-based detection methods by allowing parallel processing of multiple individual reaction trajectories.