Where no lab has gone before: Single-Molecule Electrokinetic Traps
(PhysOrg.com) -- To study the behavior of large protein complexes and long DNA chains in solution, researchers use so-called molecular traps. However, earlier traps have proven ineffective when working with small molecules due to the latters high diffusion. This limitation was first addressed through single-molecule immobilization techniques such as surface attachment and laser tweezers, but there were drawbacks: the former can disrupt biochemical structures, while the latter require molecules to be attached to large beads. A later trap developed at Stanford University used computer-based image capture and processing to track a single molecules Brownian motion, which it then cancels by applying variable voltage feedback. Now, however, Harvard University researchers have devised an Anti-Brownian ELectrokinetic (ABEL) trap that couples fluorescence microscopy to real-time electrokinetic feedback to trap any soluble fluorescence-capable molecule up to 800 times less massive than was previously possible.