Abstract: A method of characterizing a polypeptide, comprising providing a first capillary channel having a separation buffer disposed within, wherein the separation buffer comprises a non-crosslinked polymer solution, a buffering agent, a detergent, and a lipophilic dye. The separation buffer is provided such that, at the time of detection, the detergent concentration in the buffer is not above the critical micelle concentration. The polypeptide is introduced into one end of the capillary channel. An electric field is applied across a length of the capillary channel, which transports polypeptides of different sizes through the polymer solution at different rates. The polypeptide is then detected as it passes a point along the length of the capillary channel.

Abstract: Methods and systems for particle focusing to increase assay throughput in microscale systems are provided. The invention includes methods for providing substantially uniform flow velocity to flowing particles in microfluidic devices. Methods of sorting members of particle populations, such as cells and various subcellular components are also provided. Integrated systems in which particles are focused and/or sorted are additionally included.

Abstract: Apparatus and methods for modulating flow rates in microfluidic devices are provided. The methods involve modulating downstream pressure in the device to change the flow rate of materials in an upstream region of the device. Such methods include electrokinetic injection or withdrawal of materials through a side channel and the use of an absorbent material to induce wicking in the channel system. The apparatus provided includes a prefabricated wick in the device to provide for flow rate control. Additional methods for determining velocity of a particle and cell incubation time are also provided.

Abstract: The present invention provides microfluidic devices that comprise a body structure comprising at least a first microscale channel network disposed therein. The body structure has a plurality of ports disposed in the body structure, where each port is in fluid communication with one or more channels in the first channel network. The devices also include a cover layer comprising a plurality of apertures disposed through the cover layer. The cover layer is mated with the body structure whereby each of the apertures is aligned with a separate one of the plurality of ports.

Abstract: The present invention provides methods of electrophoretically separating macromolecular species, as well as compositions and systems useful in carrying out such methods. Specifically, the methods of the present invention comprise providing a substrate that has at least a first capillary channel disposed therein. The surface of the channel has a first surface charge associated therewith, and is filled with a water soluble surface adsorbing polymer solution that bears a net charge that is the same as the charge on the capillary surface.

Abstract: A method of characterizing a polypeptide, comprising providing a first capillary channel having a separation buffer disposed within, wherein the separation buffer comprises a non-crosslinked polymer solution, a buffering agent, a detergent, and a lipophilic dye. The separation buffer is provided such that, at the time of detection, the detergent concentration in the buffer is not above the critical micelle concentration. The polypeptide is introduced into one end of the capillary channel. An electric field is applied across a length of the capillary channel, which transports polypeptides of different sizes through the polymer solution at different rates. The polypeptide is then detected as it passes a point along the length of the capillary channel.

Abstract: The present invention provides microfluidic devices that comprise a body structure comprising at least a first microscale channel network disposed therein. The body structure has a plurality of ports disposed in the body structure, where each port is in fluid communication with one or more channels in the first channel network. The devices also include a cover layer comprising a plurality of apertures disposed through the cover layer. The cover layer is mated with the body structure whereby each of the apertures is aligned with a separate one of the plurality of ports.

Abstract: Methods and devices for delivering fluids into microfluidic device body structures are described. The methods and devices include the use of fluid manifolds which are integrated or interchangeable with device body structures. Methods of fabricating manifolds are also provided.

Abstract: Methods, apparatus and systems are provided for introducing large numbers of different materials into a microfluidic analytical device rapidly, efficiently and reproducibly. In particular, improved integrated pipettor chip configurations, e.g. sippers or electropipettors, are described which are capable of sampling extremely small amounts of material for which analysis is desired, transporting material into a microfluidic analytical channel network, and performing the desired analysis on the material.

Abstract: The present invention provides methods of electrophoretically separating macromolecular species, as well as compositions and systems useful in carrying out such methods. Specifically, the methods of the present invention comprise providing a substrate that has at least a first capillary channel disposed therein. The surface of the channel has a first surface charge associated therewith, and is filled with a water soluble surface adsorbing polymer solution that bears a net charge that is the same as the charge on the capillary surface.

Abstract: Apparatus and methods for modulating flow rates in microfluidic devices are provided. The methods involve modulating downstream pressure in the device to change the flow rate of materials in an upstream region of the device. Such methods include electrokinetic injection or withdrawal of materials through a side channel and the use of an absorbent material to induce wicking in the channel system. The apparatus provided includes a prefabricated wick in the device to provide for flow rate control. Additional methods for determining velocity of a particle and cell incubation time are also provided.

Abstract: Reactor systems that include a reaction receptacle that includes a plurality of reservoirs disposed in the surface of a substrate. The reactor system also typically includes a temperature control element having at least a first heat exchanger thermally coupled to it. The heat exchanger is, in turn, disposed within the at least one of the reservoirs whereby the heat exchanger transfers heat to or from a fluid disposed within the reservoir, which heat is conducted to or from the temperature control element.

Abstract: Devices, systems and methods for use in separating sample materials into different fractions that employ bulk fluid flow for loading of samples followed by electrophoretic separation of the sample material. Devices employ configurations that optionally allow bulk sample loading with some or no displacement of a separation matrix within a separation conduit. Methods of using these devices, and systems that incorporate these devices are also envisioned.

Abstract: Reactor systems that include a reaction receptacle that includes a plurality of reservoirs disposed in the surface of a substrate. The reactor system also typically includes a temperature control element having at least a first heat exchanger thermally coupled to it. The heat exchanger is, in turn, disposed within the at least one of the reservoirs whereby the heat exchanger transfers heat to or from a fluid disposed within the reservoir, which heat is conducted to or from the temperature control element.

Abstract: The present invention provides microfluidic devices that comprise a body structure comprising at least a first microscale channel network disposed therein. The body structure has a plurality of ports disposed in the body structure, where each port is in fluid communication with one or more channels in the first channel network. The devices also include a cover layer comprising a plurality of apertures disposed through the cover layer. The cover layer is mated with the body structure whereby each of the apertures is aligned with a separate one of the plurality of ports.

Abstract: The present invention generally provides microfluidic devices which incorporate improved channel and reservoir geometries, as well as methods of using these devices in the analysis, preparation, or other manipulation of fluid borne materials, to achieve higher throughputs of such materials through these devices, with lower cost, material and/or space requirements.

Abstract: Reactor systems that include a reaction receptacle that includes a plurality of reservoirs disposed in the surface of a substrate. The reactor system also typically includes a temperature control element having at least a first heat exchanger thermally coupled to it. The heat exchanger is, in turn, disposed within the at least one of the reservoirs whereby the heat exchanger transfers heat to or from a fluid disposed within the reservoir, which heat is conducted to or from the temperature control element.

Abstract: The present invention generally provides microfluidic devices which incorporate improved channel and reservoir geometries, as well as methods of using these devices in the analysis, preparation, or other manipulation of fluid borne materials, to achieve higher throughputs of such materials through these devices, with lower cost, material and/or space requirements.

Abstract: Methods, apparatus and systems are provided for introducing large numbers of different materials into a microfluidic analytical device rapidly, efficiently and reproducibly. In particular, improved integrated pipettor chip configurations, e.g. sippers or electropipettors, are described which are capable of sampling extremely small amounts of material for which analysis is desired, transporting material into a microfluidic analytical channel network, and performing the desired analysis on the material.

Abstract: The present invention generally provides improved methods of fabricating polymeric microfluidic devices that incorporate microscale fluidic structures, whereby the fabrication process does not substantially distort or deform such structures. The methods of the invention generally provide enhanced bonding processes for mating and bonding substrate layers to define the microscale channel networks therebetween.