Bead manipulation techniques

摘要

The invention provides a method of redistributing magnetically responsive beads in a droplet. The method may include conducting on a droplet operations surface one or more droplet operations using the droplet without removing the magnetically responsive beads from the region of the magnetic field. The droplet operations may in some cases be electrode-mediated. The droplet operations may redistribute and/or circulate the magnetically responsive beads within the droplet. In some cases, the droplet may include a sample droplet may include a target analyte. The redistributing of the magnetically responsive beads may cause target analyte to bind to the magnetically responsive beads. In some cases, the droplet may include unbound substances in a wash buffer. The redistributing of the magnetically responsive beads causes unbound substances to be freed from interstices of an aggregated set or subset of the magnetically responsive beads.

主权项

1. A droplet actuator comprising:
(a) a first substrate comprising:
(i) a droplet operations surface; and(ii) electrodes arranged for conducting one or more electrowetting-mediated droplet operations on the surface; and (b) one or more dielectrophoresis electrode configurations arranged for attracting and/or trapping one or more particles in a droplet situated on the droplet operations surface.