A method of partitioning droplets from a fluid reservoir containing particles provides a non-Poissonian distribution of dispensed droplets containing a desired number of particles. The method constitutes a method of operating an electrowetting on dielectric (EWOD) device including the steps of: inputting a fluid reservoir containing particles into the EWOD device; performing an electrowetting operation to dispense a plurality of dispensed droplets from the fluid reservoir; interrogating each droplet with a detector and determining whether each dispensed droplet has a desired number of particles; selecting dispensed droplets that contain the desired number of particles and performing an electrowetting operation to move the selected dispensed droplets to a reaction area on the EWOD device; and rejecting dispensed droplets that do not contain the desired number of particles and performing an electrowetting operation to move the rejected dispensed droplets to a holding area on the EWOD device that is different and spaced apart from the reaction area. The selected droplets may be combined, including with or without a portion of the rejected droplets and/or additional reagent, into a larger reaction droplet that may be used in subsequent reaction protocols.

Provided is a detection determining method used in detection of a testing target in a sample by amplification of the testing target and an amplifiable reagent, wherein the amplifiable reagent is provided in a number of 200 or less, the detection determining method including a determining step of determining that the testing target is present and a detection result is positive when the amplifiable reagent is amplified and the testing target is amplified, and determining that the testing target is absent or at least less than a specific copy number of the amplifiable reagent and a detection result is negative when the amplifiable reagent is amplified and the testing target is not amplified. Also provided are a detection determining device, a detection determining program, and a device used for the detection determining method.

The present invention concerns the technical field of volumetric measurement and volumetric instruments and provides novel devices and methods for the determination of the volume of a fluid.

A microfluidic system includes a microfluidic chip including a channel layer and a fluid control layer operatively connected to the channel layer, the channel layer having one or more fluid channels. The one or more channels are configured to contain a plurality of droplets. A valve control system is provided to control flow of fluid through the one or more fluid channels in the channel layer. The microfluidic system also includes a droplet impedance detection and feedback control system operatively connected to the valve control system. The droplet impedance detection and feedback control system is configured to detect at least a position of at least one droplet in a fluid channel and to send a signal to the valve control system to operate a particular valve at a particular time based on the detected position of the at least one droplet.

A microfluidic system includes: an electro-wetting on dielectric (EWOD) cartridge having an element array configured to receive liquid droplets, the element array including individual array elements each including array element circuity comprising sensing circuitry that is integrated into the array element circuitry; a microfluidic instrument that is configured to receive the EWOD cartridge and having an electrically conductive locator that is external to the EWOD cartridge; and a control system configured perform electrowetting operations by controlling actuation voltages applied to the element array to perform manipulation operations as to liquid droplets present on the element array. The control system further is configured to read an output from the sensing circuitry, determine a position of the locator relative to the element array based on the output, and determine a misalignment of the EWOD cartridge relative to the microfluidic instrument based on the position of the locator. The control system may adjust a droplet manipulation operation to compensate for the determined misalignment.

An assay-protocol-specific multi-channel fluid-dispenser cassette for an automated assay fluid dispensing system may include a structure with multiple fluid channels within the structure to contain and control respective assay fluids. Each fluid channels may have an outlet. A driver interface may be carried by the structure removably and mechanically engageable with a dispenser driver of a dispenser so that the dispenser driver can control the dispensing of fluids from the structure directly onto underlying reaction sites while each of the fluid channels remain as part of the structure. An assay-protocol-indicative cassette-type identifier may be formed in or attached to the structure and indicative of different assay protocols for all of the multiple fluid channels. The assay-protocol-cassette-type identifier may be readable by the cassette driver in response to the multi-channel fluid-dispenser cassette being removably connected to the dispenser.

A microfluidic system includes: an electro-wetting on dielectric (EWOD) cartridge having an element array configured to receive liquid droplets, the element array including individual array elements each including array element circuity comprising sensing circuitry that is integrated into the array element circuitry; a microfluidic instrument that is configured to receive the EWOD cartridge and having an electrically conductive locator that is external to the EWOD cartridge; and a control system configured perform electrowetting operations by controlling actuation voltages applied to the element array to perform manipulation operations as to liquid droplets present on the element array. The control system further is configured to read an output from the sensing circuitry, determine a position of the locator relative to the element array based on the output, and determine a misalignment of the EWOD cartridge relative to the microfluidic instrument based on the position of the locator. The control system may adjust a droplet manipulation operation to compensate for the determined misalignment.

The invention provides methods for assessing one or more predetermined characteristics or properties of a microfluidic droplet within a microfluidic channel, and regulating one or more fluid flow rates within that channel to selectively alter the predetermined microdroplet characteristic or property using a feedback control.

A method of partitioning droplets from a fluid reservoir containing particles provides a non-Poissonian distribution of dispensed droplets containing a desired number of particles. The method constitutes a method of operating an electrowetting on dielectric (EWOD) device including the steps of: inputting a fluid reservoir containing particles into the EWOD device; performing an electrowetting operation to dispense a plurality of dispensed droplets from the fluid reservoir; interrogating each droplet with a detector and determining whether each dispensed droplet has a desired number of particles; selecting dispensed droplets that contain the desired number of particles and performing an electrowetting operation to move the selected dispensed droplets to a reaction area on the EWOD device; and rejecting dispensed droplets that do not contain the desired number of particles and performing an electrowetting operation to move the rejected dispensed droplets to a holding area on the EWOD device that is different and spaced apart from the reaction area. The selected droplets may be combined, including with or without a portion of the rejected droplets and/or additional reagent, into a larger reaction droplet that may be used in subsequent reaction protocols.

A droplet dispensing apparatus includes a droplet ejection device, a microplate holder, a sheet stand, an image capturing device and a controller. The image capturing device is configured to move to a position above the sheet stand. The controller is configured to perform image processing on image data generated from an image captured by the image capturing device when the image capturing device is at the position above the test sheet on the sheet stand, to determine a size of each of test patterns formed by droplets dropped on the test sheet from the array of nozzles. The controller is further configured to generate a data file including the determined size of each of the test patterns. The test sheet colors or discolors at a place receiving a light-transmissive droplet.