The present invention provides a microchannel structure loaded with a bead having a particle size for detecting whether a biological substance exists in a sample. The microchannel structure includes a structure body for passing a sample through the microchannel structure to have a test or a treatment. The structure body includes a sample entrance having a first aperture to allow the sample passing therethrough, a resistance-increasing section connected with the sample entrance, and having a second aperture being smaller than the first aperture, a detecting section connecting with the resistance-increasing section, and a bead mooring structure coupled to the second end for mooring the bead in the detecting section. The present invention can be used to capture rare cells in a biological system, such as human blood.

A method of detecting passage of a particle into a target location includes receiving a sample on a die including a microfluidic chamber, the microfluidic chamber including a microfluidic path coupling a reservoir to a foyer, and moving the sample from the reservoir to the foyer by firing a nozzle fluidically coupled to the foyer. The method further includes detecting passage of a particle of the sample from the reservoir to the foyer via a first sensor disposed within the microfluidic path, and detecting passage of the particle into the target location via a second sensor disposed between the first sensor and the nozzle. The method includes recording in a dispense map, an indication of whether the target location includes a single particle or multiple particles based on signals measured by the first sensor and the second sensor.

An apparatus includes a flow cell body, a plurality of electrodes, an integrated circuit, and an imaging assembly. The flow cell body defines one or more flow channels and a plurality of wells. Each flow channel is configured to receive a flow of fluid. Each well is fluidically coupled with the corresponding flow channel. Each well is configured to contain at least one polynucleotide. Each electrode is positioned in a corresponding well of the plurality of wells. The electrodes are operable to effect writing of polynucleotides in the corresponding wells. The integrated circuit is operable to drive selective deposition or activation of selected nucleotides to attach to polynucleotides in the wells to thereby generate polynucleotides representing machine-written data in the wells. The imaging assembly is operable to capture images indicative of one or more nucleotides in a polynucleotide.

A specimen transfer device adapted to receive a blood sample is disclosed. The specimen transfer device includes a housing and an actuation member. A deformable material is disposed within the housing and is deformable from an initial position in which the material is adapted to hold the sample to a deformed position in which at least a portion of the sample is released from the material. A viscoelastic member is disposed within the housing between the material and the housing and between the material and the actuation member. The viscoelastic member is engaged with the actuation member and the material such that movement of the actuation member from a first position to a second position deforms the material from the initial position to the deformed position.

An apparatus includes a flow cell body, a plurality of electrodes, an integrated circuit, and an imaging assembly. The flow cell body defines one or more flow channels and a plurality of wells. Each flow channel is configured to receive a flow of fluid. Each well is fluidically coupled with the corresponding flow channel. Each well is configured to contain at least one polynucleotide. Each electrode is positioned in a corresponding well of the plurality of wells. The electrodes are operable to effect writing of polynucleotides in the corresponding wells. The integrated circuit is operable to drive selective deposition or activation of selected nucleotides to attach to polynucleotides in the wells to thereby generate polynucleotides representing machine-written data in the wells. The imaging assembly is operable to capture images indicative of one or more nucleotides in a polynucleotide.

In situ-generated microfluidic isolation structures incorporating a solidified polymer network, methods of preparation and use, compositions and kits therefor are described. The ability to introduce in real time, a variety of isolating structures including pens and barriers offers improved methods of micro-object manipulation in microfluidic devices. The in situ-generated isolation structures may be permanently or temporarily installed.

An apparatus includes a flow cell body, a plurality of electrodes, an integrated circuit, and an imaging assembly. The flow cell body defines one or more flow channels and a plurality of wells. Each flow channel is configured to receive a flow of fluid. Each well is fluidically coupled with the corresponding flow channel. Each well is configured to contain at least one polynucleotide. Each electrode is positioned in a corresponding well of the plurality of wells. The electrodes are operable to effect writing of polynucleotides in the corresponding wells. The integrated circuit is operable to drive selective deposition or activation of selected nucleotides to attach to polynucleotides in the wells to thereby generate polynucleotides representing machine-written data in the wells. The imaging assembly is operable to capture images indicative of one or more nucleotides in a polynucleotide.

A microfluidic diagnostic device comprises a base and at least one switch coupled to a portion of the base, the switch comprising a flap that is pivotable with respect to the base from a first position spaced away from the base a first distance to a second position where the flap is spaced away from the base a second distance. Both the base and the switch comprise one or more channels that permit passive transportation of an aqueous solution. The switch may be formed by bending or deforming a strip to cause the flap to be in the first position when there is less than a predetermined amount of fluid within the channel of switch. When a predetermined amount of fluid is in the channel of the switch, the flap pivots to the second position, which may be achieved through power from gravity, capillarity, and/or inherent elastic energy.

An example method includes connecting a flow cell to an instrument. The flow cell includes a flow channel including a manifold section having a manifold section swept volume and a detection section having a detection section swept volume. A ratio of the detection section swept volume to manifold section swept volume is at least 10 to 1. A first reagent is pumped through the flow channel. A first chemical reaction is performed between the first reagent and analytes positioned in the detection section. A subsequent reagent is pumped through the flow channel to flush out the remaining reagent. A concentration of at least 99.95 percent of reagent positioned in the detection section is the subsequent reagent, after pumping a total volume of the subsequent reagent through the flow channel that is equal to or less than 2.5 times a total swept volume of the manifold section plus the detection section.

An apparatus includes a flow cell body, a plurality of electrodes, an integrated circuit, and an imaging assembly. The flow cell body defines one or more flow channels and a plurality of wells. Each flow channel is configured to receive a flow of fluid. Each well is fluidically coupled with the corresponding flow channel. Each well is configured to contain at least one polynucleotide. Each electrode is positioned in a corresponding well of the plurality of wells. The electrodes are operable to effect writing of polynucleotides in the corresponding wells. The integrated circuit is operable to drive selective deposition or activation of selected nucleotides to attach to polynucleotides in the wells to thereby generate polynucleotides representing machine-written data in the wells. The imaging assembly is operable to capture images indicative of one or more nucleotides in a polynucleotide.