Abstract: High throughput screening of crystallization of a target material is accomplished by simultaneously introducing a solution of the target material into a plurality of chambers of a microfabricated fluidic device. The microfabricated fluidic device is then manipulated to vary the solution condition in the chambers, thereby simultaneously providing a large number of crystallization environments. Control over changed solution conditions may result from a variety of techniques, including but not limited to metering volumes of crystallizing agent into the chamber by volume exclusion, by entrapment of volumes of crystallizing agent determined by the dimensions of the microfabricated structure, or by cross-channel injection of sample and crystallizing agent into an array of junctions defined by intersecting orthogonal flow channels.

Abstract: A static fluid and a second fluid are placed into contact along a microfluidic free interface and allowed to mix by diffusion without convective flow across the interface. In accordance with one embodiment of the present invention, the fluids are static and initially positioned on either side of a closed valve structure in a microfluidic channel having a width that is tightly constrained in at least one dimension. The valve is then opened, and no-slip layers at the sides of the microfluidic channel suppress convective mixing between the two fluids along the resulting interface. Applications for microfluidic free interfaces in accordance with embodiments of the present invention include, but are not limited to, protein crystallization studies, protein solubility studies, determination of properties of fluidics systems, and a variety of biological assays such as diffusive immunoassays, substrate turnover assays, and competitive binding assays.

Abstract: A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

Abstract: High throughput screening of crystallization of a target material is accomplished by simultaneously introducing a solution of the target material into a plurality of chambers of a microfabricated fluidic device. The microfabricated fluidic device is then manipulated to vary the solution condition in the chambers, thereby simultaneously providing a large number of crystallization environments. Control over changed solution conditions may result from a variety of techniques, including but not limited to metering volumes of crystallizing agent into the chamber by volume exclusion, by entrapment of volumes of crystallizing agent determined by the dimensions of the microfabricated structure, or by cross-channel injection of sample and crystallizing agent into an array of junctions defined by intersecting orthogonal flow channels.

Abstract: A method to suppress biofilm formation in a growth chamber of a chemostat is described. The method includes the steps of adding a lysis agent to an isolated portion of the growth chamber, and reuniting the isolated portion with the rest of the growth chamber. The microfluidic chemostat includes a growth chamber having a plurality of compartments. Each of the compartments may be fluidly isolated from the rest of the growth chamber by one or more actuatable valves. The chemostat also included a nutrient supply-line to supply growth medium to the growth chamber, and an output port to remove fluids from the growth chamber.

Abstract: High throughput screening of crystallization of a target material is accomplished by simultaneously introducing a solution of the target material into a plurality of chambers of a microfabricated fluidic device. The microfabricated fluidic device is then manipulated to vary the solution condition in the chambers, thereby simultaneously providing a large number of crystallization environments. Control over changed solution conditions may result from a variety of techniques, including but not limited to metering volumes of crystallizing agent into the chamber by volume exclusion, by entrapment of volumes of crystallizing agent determined by the dimensions of the microfabricated structure, or by cross-channel injection of sample and crystallizing agent into an array of junctions defined by intersecting orthogonal flow channels.

Abstract: A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

Abstract: The present invention provides microfluidic devices and methods using the same in various types of thermal cycling reactions. Certain devices include a rotary microfluidic channel and a plurality of temperature regions at different locations along the rotary microfluidic channel at which temperature is regulated. Solution can be repeatedly passed through the temperature regions such that the solution is exposed to different temperatures. Other microfluidic devices include an array of reaction chambers formed by intersecting vertical and horizontal flow channels, with the ability to regulate temperature at the reaction chambers. The microfluidic devices can be used to conduct a number of different analyzes, including various primer extension reactions and nucleic acid amplification reactions.

Abstract: Sieve valves for use in microfluidic device are provided. The valves are useful for impeding the flow of particles, such as chromatography beads or cells, in a microfluidic channel while allowing liquid solution to pass through the valve. The valves find particular use in making microfluidic chromatography modules.

Abstract: A static fluid and a second fluid are placed into contact along a microfluidic free interface and allowed to mix by diffusion without convective flow across the interface. In accordance with one embodiment of the present invention, the fluids are static and initially positioned on either side of a closed valve structure in a microfluidic channel having a width that is tightly constrained in at least one dimension. The valve is then opened, and no-slip layers at the sides of the microfluidic channel suppress convective mixing between the two fluids along the resulting interface. Applications for microfluidic free interfaces in accordance with embodiments of the present invention include, but are not limited to, protein crystallization studies, protein solubility studies, determination of properties of fluidics systems, and a variety of biological assays such as diffusive immunoassays, substrate turnover assays, and competitive binding assays.

Abstract: The present invention provides microfluidic devices and methods using the same in various types of thermal cycling reactions. Certaom devices include a rotary microfluidic channel and a plurality of temperature regions at different locations along the rotary microfluidic channel at which temperature is regulated. Solution can be repeatedly passed through the temperature regions such that the solution is exposed to different temperatures. Other microfluidic devices include an array of reaction chambers formed by intersecting vertical and horizontal flow channels, with the ability to regulate temperature at the reaction chambers. The microfluidic devices can be used to conduct a number of different analyses, including various primer extension reactions and nucleic acid amplification reactions.

Abstract: A chemostat is described that includes a growth chamber having a plurality of compartments. Each of the compartments may be fluidly isolated from the rest of the growth chamber by one or more actuatable valves. The chemostat may also include a nutrient supply-line to supply growth medium to the growth chamber, and an output port to remove fluids from the growth chamber. Also, a method of preventing biofilm formation in a growth chamber of a chemostat is described. The method may include the steps of adding a lysis agent to a isolated portion of the growth chamber, and reuniting the isolated portion with the rest of the growth chamber.

Abstract: A static fluid and a second fluid are placed into contact along a microfluidic free interface and allowed to mix by diffusion without convective flow across the interface. In accordance with one embodiment of the present invention, the fluids are static and initially positioned on either side of a closed valve structure in a microfluidic channel having a width that is tightly constrained in at least one dimension. The valve is then opened, and no-slip layers at the sides of the microfluidic channel suppress convective mixing between the two fluids along the resulting interface. Applications for microfluidic free interfaces in accordance with embodiments of the present invention include, but are not limited to, protein crystallization studies, protein solubility studies, determination of properties of fluidics systems, and a variety of biological assays such as diffusive immunoassays, substrate turnover assays, and competitive binding assays.

Abstract: The present invention relates to microfluidic devices and methods facilitating the growth and analysis of crystallized materials such as proteins. In accordance with one embodiment, a crystal growth architecture is separated by a permeable membrane from an adjacent well having a much larger volume. The well may be configured to contain a fluid having an identity and concentration similar to the solvent and crystallizing agent employed in crystal growth, with diffusion across the membrane stabilizing that process. Alternatively, the well may be configured to contain a fluid having an identity calculated to affect the crystallization process. In accordance with the still other embodiment, the well may be configured to contain a material such as a cryo-protectant, which is useful in protecting the crystalline material once formed.

Abstract: The use of microfluidic structures enables high throughput screening of protein crystallization. In one embodiment, an integrated combinatoric mixing chip allows for precise metering of reagents to rapidly create a large number of potential crystallization conditions, with possible crystal formations observed on chip. In an alternative embodiment, the microfluidic structures may be utilized to explore phase space conditions of a particular protein crystallizing agent combination, thereby identifying promising conditions and allowing for subsequent focused attempts to obtain crystal growth.

Abstract: A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

Abstract: A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

Abstract: A chemostat is described that includes a growth chamber having a plurality of compartments. Each of the compartments may be fluidly isolated from the rest of the growth chamber by one or more actuatable valves. The chemostat may also include a nutrient supply-line to supply growth medium to the growth chamber, and an output port to remove fluids from the growth chamber. Also, a method of preventing biofilm formation in a growth chamber of a chemostat is described. The method may include the steps of adding a lysis agent to a isolated portion of the growth chamber, and reuniting the isolated portion with the rest of the growth chamber.

Abstract: High throughput screening of crystallization of a target material is accomplished by simultaneously introducing a solution of the target material into a plurality of chambers of a microfabricated fluidic device. The microfabricated fluidic device is then manipulated to vary the solution condition in the chambers, thereby simultaneously providing a large number of crystallization environments. Control over changed solution conditions may result from a variety of techniques, including but not limited to metering volumes of crystallizing agent into the chamber by volume exclusion, by entrapment of volumes of crystallizing agent determined by the dimensions of the microfabricated structure, or by cross-channel injection of sample and crystallizing agent into an array of junctions defined by intersecting orthogonal flow channels.

Abstract: The present invention relates to microfluidic devices and methods facilitating the growth and analysis of crystallized materials such as proteins. In accordance with one embodiment, a crystal growth architecture is separated by a permeable membrane from an adjacent well having a much larger volume. The well may be configured to contain a fluid having an identity and concentration similar to the solvent and crystallizing agent employed in crystal growth, with diffusion across the membrane stabilizing that process. Alternatively, the well may be configured to contain a fluid having an identity calculated to affect the crystallization process. In accordance with the still other embodiment, the well may be configured to contain a material such as a cryo-protectant, which is useful in protecting the crystalline material once formed.