Microfluidic analytical device

Inventors

Isaac, Thomas Henry • Cunha, Pedro • SHERIDAN, Eoin • Love, David • Palmer, Rebecca • Kelly, Douglas J. • PODD, Gareth

Assignees

Lightcast Discovery Ltd

Abstract

A device comprising: a first zone comprising an attachment site; a first pathway; a second pathway and a means for creating a second medium comprised of aqueous microdroplets in a carrier; a microdroplet manipulation zone comprising: a first composite wall comprised of a first transparent substrate; a first transparent conductor layer on the substrate; a photoactive layer activated by electromagnetic radiation; and a first dielectric layer on the conductor layer; a second composite wall comprised of a second substrate; a second conductor layer on the substrate; and optionally a second dielectric layer on the conductor layer; an A/C source; a source of first electromagnetic radiation; means for manipulating the points of impingement of the electromagnetic radiation on the photoactive layer; an detection zone disposed downstream of the microdroplet manipulation zone or integral therewith; and a fluorescence or Raman-scattering detection system.

Core Innovation

A microfluidic analytical device manipulates and interrogates microdroplets for nucleic acid analyte sequencing, including DNA/RNA. The device includes an attachment site and uses progressive pyrophosphorolysis at the attachment site to generate nucleoside triphosphates, which are isolated into aqueous microdroplets within a microfluidic space with a water-immiscible carrier.

The device further includes an optically-mediated electrowetting (oEWOD) microdroplet manipulation zone that uses a double-composite transparent wall stack with transparent conductor layers, a photoactive semiconductor layer, and a thin dielectric layer. An AC source biases the stack, while pixelated electromagnetic radiation, created using a reflective screen illuminated by light from LEDs, rapidly creates highly complex patterns of ephemeral electrowetting locations, including concomitantly running first electrowetting pathways and second electrowetting pathways that intercept with the first electrowetting pathways to create microdroplet-coalescing locations.

Microdroplets at the microdroplet-coalescing locations are interrogated using a second electromagnetic radiation source, and emitted fluorescence or Raman-scattering is detected by photodetectors. The detection reads fluorophores released from non-fluorescing oligonucleotide probes, and the device supports downstream fluorescence or Raman interrogation associated with interrogation of microdroplets at specified locations.

Claims Coverage

The independent claim is directed to manipulating many thousands of microdroplets simultaneously on a microfluidic chip using optically-mediated electrowetting (oEWOD) with pixelated, reflective-screen patterns that steer droplets, including pathway intersections that create microdroplet-coalescing locations. It further covers interrogating the microdroplets at those locations by detecting fluorescence or Raman-scattering emitted by each microdroplet.

Across the independent claim and its directly linked refinements, the method centers on pixelated reflective-screen oEWOD to steer many microdroplets in parallel, using intersecting electrowetting pathways to form microdroplet-coalescing locations, followed by interrogation at those locations with detection of fluorescence or Raman-scattering.

Stated Advantages

Documented Applications