Provided in part herein are pipette tip rack assemblies having one or more of the following features: (i) having a plurality of pipette tip receptacle plates, each plate having an array of pipette tips, stacked upon one another supported by a rack base; (ii) each plate having one or more projections from the proximal or distal surface and, optionally, orifices that oppose the projections of the next plate in the stack, and (iii) the rack base having a proximal surface with one or more orifices or projections that oppose the projections or orifices of the plate in the stack. Also provided are methods of dispensing pipette tips from pipette tip rack assemblies and manufacturing pipette tip rack assembly components.

The present technology generally relates to stopped-flow microfluidic devices. Select embodiments of the present technology include microfluidic devices having a first porous element configured to receive a first fluid and a second porous element configured to receive a second fluid. The second porous element can have one or more legs overlapping with the first porous element. The device can be configured such that (a) delivery of the first fluid to the first porous element causes the first fluid to flow along the length of the first porous element without substantially wetting the one or more legs, and (b) delivery of the second fluid to the second porous element causes the second fluid to flow into the overlapping regions of the first porous element, thereby substantially stopping flow of the first fluid along at least a portion of the first porous element.

The two-dimensional material (such as graphene, hBN) based Paper Microfluidic Device will detect various analytes, which can be related to disease conditions, to minimize guesswork for a common individual to recognize a certain analyte, and faster confirmation of analytes for professionals. It will enable to predict an increase of analyte concentrations through machine learning, be applicable in both medical and non-medical fields, have a refill enclosure, and a GPS activated app to contact nearby critical infrastructure in cases of medical applications. This will have the ability to detect analytes far faster than any traditional analyte detection systems in both medical and non-medical fields.

Disclosed herein are cellular cassettes for the storage, collection, and analysis of biological samples. The cellular cassette can enable easy sample collection and sealing of microwell arrays with semi-permeable membrane for stable storage and future processing of single cells. Also disclosed herein are systems and kits comprising one or more described cassettes. The described cassettes, systems, and kits can be used to create barcoded, single-cell sequencing libraries. Further described herein are methods of using the cassettes, systems, and kits.

According to a first aspect, the present invention is embodied as a method of processing a filtered liquid with a microfluidic device. The method includes positioning a porous filtering medium with respect to the microfluidic device, so as to allow a flow path between the filtering medium and a channel of the microfluidic device. The method further includes introducing a liquid in the porous filtering medium for the liquid to advance along the filtering medium and be filtered by the medium. The method further includes applying compression to the filtering medium to extract a given volume of the filtered liquid from the filtering medium, where the extracted liquid volume reaches said channel via the flow path. The method further includes processing the extracted volume with the microfluidic device.

The present invention provides a device for detecting an analyte in a sample, including a chamber for receiving a testing element, where the testing element has a first position and a second position in the chamber; the testing element is not in contact with a fluid sample when the testing element is located in the first position, and the testing element is in contact with a fluid sample when the testing element is located in the second position.

The present disclosure provides methods and systems for detecting a presence or absence of analytes. The systems may comprise membrane-based substrates.

Diagnostic devices for quantitative or qualitative analysis of a sample fluid including an analyte include at least two portions made from a hydrophilic material. The planar portions are stacked on each other and each occupy a different and substantially parallel plane to form a three-dimensional structure. At least one of the planar portions includes a hydrophobic region formed by applying a low surface energy material that extends through a thickness of the substrate portion from a first major surface to a second major surface thereof. The hydrophilic regions in the overlying substantially parallel substrate portions can be aligned with each other such that a fluid is passively transported between adjacent hydrophilic regions to provide a sample flow path between adjacent substrate portions.

A multiplexed testing strip testing device includes a hydrophobic paper-based strip housing element configured for placement of one or more testing strips. One or more alignment markers on the hydrophobic paper-based housing element are marked to facilitate placement of the one or more testing strips. A cover element is arranged above the strip housing element and includes a machine-readable test identifier on an upper surface. A removably attached filtering element is arranged on the hydrophobic paper-based strip housing element.

The present invention relates to a low-cost, thermally reversible valve for paper-fluidic diagnostic devices. In particular, this invention demonstrates a tunable valve mechanism fabricated by wax-ink printing and localized heating via thin-film resistors to sequentially release liquids through a cellulose or nitrocellulose membrane. The wax-ink valve can obstruct fluid flow for a sustained time and are thermally actuated to release a controlled amount of liquid past the valve. This integrated paper-fluidic diagnostic assay device requires minimal user involvement, can be easily manufactured and tuned to meet various fluid delivery timing and incubation needs.