Droplet actuator devices and methods employing magnetic beads

摘要

A method of providing a droplet in contact with a magnetically responsive bead and having a reduced quantity of a substance. The method generally includes the steps of (a) providing a droplet actuator (200) comprising: (i) a substrate (210) comprising electrodes (214) arranged for conducting droplet operations on a surface; (ii) a starting droplet (218/222) comprising: (1) one or more magnetically responsive beads (220); (2) a starting quantity of the substance; and (3) a starting volume; (b) magnetically immobilizing the one or more magnetically responsive beads at a location which is at a distance from a target droplet splitting zone, (224); (c) conducting one or more droplet operations comprising droplet dividing operations selected to divide the combined droplet to yield a set of droplets comprising: (i) a droplet (218) comprising substantially all of the one or more magnetically responsive beads and having a decreased quantity of the substance relative to the starting concentration; and (ii) a droplet (222) substantially lacking the magnetically responsive beads.

主权项

1. A method of providing a droplet in contact with magnetically responsive beads and having a reduced quantity of a substance, the method comprising:
(a) providing a droplet actuator comprising:
(i) magnet sets and electrode sets, wherein:
(1) each electrode set comprises one or more electrodes associated with a substrate;(2) two or more electrode sets are arranged to form an array of electrodes and configured for conducting one or more droplet operations;(3) each magnet set comprises one or more magnets;(4) each magnet set is arranged in a relationship with an electrode set such that magnetic field(s) exerted by the magnet set restricts a mobility of the magnetically responsive beads to a locus which is proximate to the electrode set; and(5) each magnet set is arranged in relationship to an adjacent magnet set(s), which relationship is a polar opposite to a polar orientation of the adjacent magnet set;(ii) a starting droplet associated with each electrode set, each starting droplet comprising:
(1) magnetically responsive beads;(2) a starting quantity of the substance; and(3) a starting volume; (b) conducting one or more droplet operations to merge a wash droplet with each starting droplet to yield a combined droplet associated with each electrode set; (c) magnetically immobilizing the magnetically responsive beads at a target droplet splitting zone on each electrode set; (d) conducting one or more droplet operations comprising droplet dividing operations selected to divide the combined droplet at the droplet splitting zone to yield a set of droplets on each electrode set comprising:
(i) a droplet comprising substantially all of the magnetically responsive beads and having a decreased quantity of the substance relative to the starting concentration; and(ii) a droplet substantially lacking the magnetically responsive beads; and wherein (d) is conducted without removing the magnet set immobilizing the magnetically responsive beads.