Magnetic particle extraction in EWOD instruments

Abstract

A method of operation of an EWOD apparatus for separating magnetically responsive particles from polar droplets using a magnetic field. The method comprises the steps of: dispensing a droplet onto an array of elements of an EWOD device, wherein the droplet comprises magnetically responsive particles; performing an electrowetting operation to move the droplet along the array of elements to a position relative to a magnet element proximate to the EWOD device; operating the magnet element to apply a magnetic field to the droplet, wherein at least a portion of the magnetically responsive particles are gathered within the droplet in response to the magnetic field; and separating the aggregated magnetically responsive particles from the droplet using the magnetic field, wherein the aggregated magnetically responsive particles move to a location on the array of elements proximate the magnet element in response to the magnetic field. Embodiments of a method of the present application may be executed by an EWOD control system executing program code stored on a non-transitory computer readable medium.

Description

technical field [0001] The present invention relates to droplet microfluidic devices, and more particularly to active matrix electrowetting on dielectric (AM-EWOD) devices, and methods for manipulating and separating magnetically responsive particles from fluidic droplets in microfluidic devices. Background technique [0002] Electrowetting on dielectrics (EWOD) is a well-known technique for manipulating fluid droplets by applying an electric field. Active Matrix EWOD (AM-EWOD) refers to realizing EWOD in an active matrix array including transistors, for example by using thin film transistors (TFTs). Therefore, it is a candidate technology for digital microfluidics for lab-on-a-chip technology. In "Digital Microfluidics: Is a Lab-on-a-Chip Really Possible?" "(Digital microfluidics: is a true lab-on-a-chippossible?), R.B. Fair, Microfluid Nanofluid (2007) 3: 245-281), find the basic principle introduction of this technology. [0003] figure 1 is a diagram depicting an exe...

AI Technical Summary

Problems solved by technology

Because magnetic particle separation is performed by splitting the droplet using electrowetting operations, such conventional methods result in large amounts of liquid in the droplet accompanying the bead after splitting, which is undesirable because the bead (and any associated target particles) for maximum isolation

Furthermore, the cleaning and separation processes require a significant amount of space on the EWOD device array relative to the entire array area

This limits the space that can be used for other EWOD operations, reducing the overall efficiency and usefulness of the EWOD equipment

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