Abstract: A microdevice is provided for controlling fluid flow. The microdevice includes a substantially planar contact surface and a plurality of fluid-transporting features associated therewith. Also included is a substrate having a substantially planar contact surface and a fluid-transporting feature associated therewith. The contact surfaces are positioned in slidable and fluid-tight contact to allow for controllable formation of a plurality of different flow paths upon alignment of the substrate fluid-transporting feature with each cover plate fluid-transporting features in succession. Typically, at least one of the cover plate and substrate is comprised of a biofouling resistant polymer, and the flow paths are of different lengths. Optionally, a plurality of fluid-transporting features is associated with the substrate so that flow paths are formed as a result of a different alignment of the fluid-transporting features.

Abstract: A microdevice is provided for controlling fluid flow. The microdevice includes a substantially planar contact surface and a plurality of fluid-transporting features associated therewith. Also included is a substrate having a substantially planar contact surface and a fluid-transporting feature associated therewith. The contact surfaces are positioned in slidable and fluid-tight contact to allow for controllable formation of a plurality of different flow paths upon alignment of the substrate fluid-transporting feature with each cover plate fluid-transporting features in succession. Typically, at least one of the cover plate and substrate is comprised of a biofouling resistant polymer, and the flow paths are of different lengths. Optionally, a plurality of fluid-transporting features is associated with the substrate so that flow paths are formed as a result of a different alignment of the fluid-transporting features.

Abstract: A polyaryl-ether-ketone (PAEK)-based microfluidic device having an integrated electrospray emitter is disclosed. Bonding of at least one PAEK substrate forming the microfluidic device is accomplished using a solvent-resistant adhesive, such as a polyimide-based adhesive, in combination with an adhesion enhancement treatment. By providing the PAEK-based microfluidic device with an integrated electrospray emitter, efficient and effective analysis of fluid samples is enabled.

Abstract: The present invention relates to a microdevice having a valve structure that contains low or no dead volume. The microdevice comprises a substrate and a cover plate each having a substantially planar contact surface and each contact surface having a fluid-transporting feature associated therewith. The substrate contact surface is positioned in slidable and fluid-tight contact with the cover plate contact surface to allow for controllable alignment between the fluid-transporting features. As a result, fluid communication is provided therebetween through a small area. Where the cover plate fluid-transporting feature comprises a conduit, the conduit may have a substantially constant cross-sectional area. The controllable alignment between the fluid-transporting features may form an alignment-dependent variable-length flow path.

Abstract: The present invention relates to a microfluidic device for separating the components of a fluid sample. A cover plate is arranged over the first surface of a substrate, which, in combination with a microchannel formed in the first surface, defines a separation conduit for separating the components of the fluid sample. An inlet port in fluid communication with the separation conduit allows a mobile phase containing a gradient of a selected mobile-phase component to be introduced from an integrated gradient-generation means to the separation conduit. A method is also provided for separating the components of a fluid sample using a mobile phase containing a gradient of a selected mobile-phase component, wherein the gradient is generated within a small volume of mobile phase.

Abstract: A planar extensible structure in a flat planar flex circuit can be extended out of the plane of the circuit by a distance of more than the width of the structure to carry fluids, electrical signals or optical signals into and out of the circuit. The planar extensible structure may be an Archimedes spiral, a parabolic spiral, a polygonal spiral, a non-spiral extensible shape, or other extensible shape. The invention can be used to siphon fluid samples from each well in a multiple-well microtiter plate into a microfluidic manifold for utility in chemical and biochemical analysis. The invention can also be used to allow electrical interconnect between adjacent circuits or circuit boards, and can allow signals carried in optical fibers to be transferred between optical circuits in different planes.

Abstract: The present invention relates to a microdevice for separating the components of a fluid sample. A cover plate is arranged over the first surface of a substrate, and, in combination with a microchannel formed in the first surface, defines a separation conduit for separating the components of the fluid sample. A sample inlet port in fluid communication with the conduit allows a fluid sample introduced from a sample source to be conveyed in a defined sample flow path such that the sample fluid travels, in order, through the sample inlet port, the separation conduit and a sample outlet port. The microdevice also includes an integrated introducing means for controllably introducing a volume of the fluid sample from a sample source into the sample inlet port and through the separation conduit. A method for separating the components of a fluid sample using the microdevice is also provided.

Abstract: The present invention relates to a microdevice having a valve structure that contains low or no dead volume. The microdevice comprises a substrate and a cover plate each having a substantially planar contact surface and each contact surface having a fluid-transporting feature associated therewith. The substrate contact surface is positioned in slidable and fluid-tight contact with the cover plate contact surface to allow for controllable alignment between the fluid-transporting features. As a result, fluid communication is provided therebetween through a small area. Where the cover plate fluid-transporting feature comprises a conduit, the conduit may have a substantially constant cross-sectional area. The controllable alignment between the fluid-transporting features may form an alignment-dependent variable-length flow path.

Abstract: A modified Salmonella, wherein the wild type pag gene such as pagC has been replaced by a gene encoding a truncated pag gene such as pagC gene fused to a heterologous DNA segment, is disclosed. This modification significantly attenuates the virulence of the Salmonella. In addition, immune reaction to the portion of the fusion protein encoded by the heterologous gene can be generated. Uses of the vector, including its use in a drug screen are also disclosed.

Abstract: A DNA encoding an immunologically cross-reactive form of diphtheria toxin Fragment A, wherein the codons corresponding to Val-147 and Glu-148 of naturally-occurring diphtheria toxin are deleted from the DNA.