Abstract: Interrogation of surface receptors of individual cells within a population of cell types in a single mixture is described. Each cell comprises, bound to target surface receptors on the cell, a collection of binding compositions, each comprising a distinct molecular tag. A continuous flow of cell medium containing the cells is pneumatically transported through a channel in a separation device, toward a cleavage/release zone, where specific tags correlating to each binding composition, and thus to each corresponding cell surface receptor, are released from the binding compositions on the cell surface. The method is effective to produce a separately detectable collection of tag signals for each cell.

Abstract: Improved sealing for microstructures in microfluidic devices having a plurality of units is provided by providing collars surrounding the openings to the microstructures, such as reservoirs. The collars are protrusions extending from the surface of the devices and the internal walls of the collars generally aligned with the internal walls of the microstructure. Conformable and/or adhesive lids are employed for sealing the microstructures.

Abstract: Microfluidic devices are provided having units of 8-fold symmetry comprising 8 assay units, where a reservoir provides a common component to 8 assay units. The units can be compactly formed in a substrate to provide the ability to perform a large number of assays within a small area. The microfluidic devices find use in operations, such as assays, DNA sequence detection, etc. Various formats can be used to have the microfluidic device interrelate with microtiter well plates. Methods are provided for monitoring the flow rates/velocities of assay components and streams for comparison of results in different assay units and/or to modify the conditions to change the flow rates in particular channels.

Abstract: Interrogation of surface receptors of individual cells within a population of cell types in a single mixture is described. Each cell comprises, bound to target surface receptors on the cell, a collection of binding compositions, each comprising a distinct molecular tag. A continuous flow of cell medium containing the cells is pneumatically transported through a channel in a separation device, toward a cleavage/release zone, where specific tags correlating to each binding composition, and thus to each corresponding cell surface receptor, are released from the binding compositions on the cell surface. The method is effective to produce a separately detectable collection of tag signals for each cell.

Abstract: Devices and methods are provided using microfluidic devices for manipulating small volumes and determining a variety of chemical and physical events. The devices rely upon an opening to the atmosphere of a small volume in a zone, where a sample is placed in the zone where evaporation can occur. The zone is maintained in contact with a liquid medium that serves to replenish the liquid in the zone and maintain the composition of the mixture in the zone substantially constant. The diffusion of components in the zone is restricted during the course of the determination by the liquid flux into the zone.

Abstract: Devices and methods are provided using microfluidic devices for manipulating small volumes and determining a variety of chemical and physical events. The devices rely upon an opening to the atmosphere of a small volume in a zone, where a sample is placed in the zone where evaporation can occur. The zone is maintained in contact with a liquid medium that serves to replenish the liquid in the zone and maintain the composition of the mixture in the zone substantially constant. The diffusion of components in the zone is restricted during the course of the determination by the liquid flux into the zone.

Abstract: Devices and methods are provided using microfluidic devices for manipulating small volumes and determining a variety of chemical and physical events. The devices rely upon an opening to the atmosphere of a small volume in a zone, where a sample is placed in the zone where evaporation can occur. The zone is maintained in contact with a liquid medium that serves to replenish the liquid in the zone and maintain the composition of the mixture in the zone substantially constant. The diffusion of components in the zone is restricted during the course of the determination by the liquid flux into the zone.

Abstract: Devices and methods are provided using microfluidic devices for manipulating small volumes and determining a variety of chemical and physical events. The devices rely upon an opening to the atmosphere of a small volume in a zone, where a sample is placed in the zone where evaporation can occur. The zone is maintained in contact with a liquid medium that serves to replenish the liquid in the zone and maintain the composition of the mixture in the zone substantially constant. The diffusion of components in the zone is restricted during the course of the determination by the liquid flux into the zone.