Electrokinetic Microfluidic Flow Cytometer Apparatuses with Differential Resistive Particle Counting and Optical Sorting
AssigneeDiagnostic Chips, LLC
InventorDongqing Li
Life of this patent
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Abstract
The present invention provides electrokinetic microfluidic cytometers useful for detecting and/or sorting fluid-borne particles. In some embodiments, the electrokinetic microfluidic flow cytometer apparatus comprises a substrate having a microchannel formed therein, a particle-sensing gate that reduces the cross-sectional area of a portion of the microchannel, a pair of signal- and noise-detection electrodes, and a particle-detection circuit that is electrically connected to the signal- and noise-detection electrodes and is configured to generate a particle-detection signal responsive to differences in resistivity across the particle-sensing gate.
Claims26
An electrokinetic microfluidic flow cytometer apparatus, comprising:
- a substrate having defined therein an input port, an output port, and a microchannel that fluidly connects the input port and the output port to allow a particle-carrying fluid to flow therebetween;
- a particle-sensing gate that reduces the cross-sectional area of a portion of the microchannel;
- a pair of signal- and noise-detection electrodes, each mounted in or on a surface of the microchannel;
- and
- a particle-detection circuit electrically connected to the signal- and noise-detection electrodes,
- wherein one of the signal- and noise-detection electrodes is positioned upstream of the particle-sensing gate and the other is positioned downstream of the particle-sensing gate, and
- wherein the particle-detection circuit is configured to generate a particle-detection signal responsive to changes in resistivity across the particle-sensing gate as particles flow through the particle-sensing gate, while at least substantially canceling a common component of ambient electrical noise received by the signal- and noise-detection electrodes.
An electrokinetic microfluidic flow cytometer apparatus, comprising:
- a substrate having defined therein an input port, a plurality of particle-sorting output ports, and a microchannel that fluidly connects the input port and the plurality of particle-sorting output ports to allow a particle-carrying fluid to flow therebetween responsive to an electric field along the microchannel;
- a light source configured to emit at least two wavelengths of light to illuminate an optical-detection region of the microchannel;
- a first primary photodetector positioned above the substrate and configured to detect a first wavelength of light emitted from particles as they flow through the optical-detection region of the microchannel and to generate a first output signal responsive thereto, the first output signal containing a first noise component;
- a second primary photodetector positioned beneath the substrate and configured to detect a second wavelength of light emitted from particles as they flow through the optical-detection region of the microchannel and to generate a second output signal responsive thereto, the second output signal containing a second noise component;
- a reference photodetector configured to generate a reference noise signal that is not responsive to light emitted from particles as they flow through the optical-detection region and is characteristic of the first and second noise components;
- and
- a first comparator circuit configured to generate a first particle-characterization signal responsive to a difference between the first output signal and the reference noise signal so that the first particle-characterization signal is at least substantially free of the noise component from the first output signal;
- and
- a second comparator circuit configured to generate a second particle-characterization signal responsive to a difference between the second output signal and the reference noise signal so that the second particle-characterization signal is at least substantially free of the noise component from the second output signal,
Dependencies are inferred from the claim text.