The hardware-based Anti-Brownian ELectrokinetic trap (ABEL trap) features a feedback latency as short as 25 μs,
suitable for trapping single protein molecules in aqueous solution. The performance of the feedback control loop is
analyzed to extract estimates of the position variance for various controller designs. Preliminary data are presented in
which the trap is applied to the problem of determining the distribution of numbers of ATP bound for single chaperonin
The Anti-Brownian Electrophoretic trap (ABEL trap) allows a user to trap and manipulate individual fluorescent molecules in solution. The heart of the ABEL trap is a microfluidic cell. In previous incarnations of the ABEL trap, the microfluidic cell was formed from a polydimethylsiloxane (PDMS) stamp and a glass coverslip. Here we present an improved microfluidic cell, made entirely out of glass. This new design significantly decreases the rate of photobleaching, which previously limited the time that a single molecule could be trapped. Chemical modifications to the surface of the cell prevent adsorption and allow one to control the balance between electroosmotic and electrophoretic forces. The depth of the trapping region in the cell can be adjusted to allow trapping of different-sized objects.
The Anti-Brownian ELectrophoretic trap (ABEL trap) is a new device that allows a user to trap and manipulate fluorescent objects as small as 20 nm freely diffusing in solution. We describe in detail how to build an ABEL trap.