Abstract: A microscopic lens, of size approximately 1 micron is used for its optical characteristics.

Abstract: A microscopic lens, of size approximately 1 micron is used for its optical characteristics.

Abstract: Techniques for processing gene expression data and predicting gene relationships are provided. More specifically, a method for processing gene expression ratios may include discretizing a first expression ratio for a first gene and a second expression ratio for a second gene for each of a plurality of experiments into one of three indications, calculating the probability that the combination of the discretized expression ratios for each of the plurality of experiments arises by random chance, and determining whether the first gene and the second gene are related.

Abstract: This invention provides an extraction device and a method for extracting desired particles from a sample stream containing the desired particles. The device has a sample stream inlet, an extraction stream inlet, and an extraction channel in fluid communication with the sample stream inlet and the extraction stream inlet. The extraction channel is for receiving a sample stream from the sample stream inlet in adjacent laminar flow with an extraction stream from the extraction stream inlet. A sequestering material within the extraction channel captures desired particles in the extraction stream. A by-product stream outlet in fluid communication with the extraction channel receives a by-product stream comprising at least a portion of the sample stream form which desired particles have been extracted. A product outlet in fluid communication with the extraction channel receives a product which has the sequestering material and at least a portion of the desired particles.

Abstract: A microscopic lens, of size approximate 1 micron is used for its optical characteristics.

Abstract: Techniques for processing gene expression data and predicting gene relationships are provided. More specifically, a method for processing gene expression ratios may include discretizing a first expression ratio for a first gene and a second expression ratio for a second gene for each of a plurality of experiments into one of three indications, calculating the probability that the combination of the discretized expression ratios for each of the plurality of experiments arises by random chance, and determining whether the first gene and the second gene are related.

Abstract: This invention provides microfabricated systems for extraction of desired particles from a sample stream containing desired and undesired particles. The sample stream is placed in laminar flow contact with an extraction stream under conditions in which inertial effects are negligible. The contact between the two streams is maintained for a sufficient period of time to allow differential transport of the desired particles from the sample stream into the extraction stream. In a preferred embodiment the differential transport mechanism is diffusion. The extraction system of this invention coupled to a microfabricated diffusion-based mixing device and/or sensing means allows picoliter quantities of fluid to be processed or analyzed on devices no larger than silicon wafers. Such diffusion-based mixing or sensing devices are preferably channel cell systems for detecting the presence and/or measuring the quantity of analyte particles in a sample stream.

Abstract: A microfilter utilizing the principles of tangential flow to prevent clogging, and sloped channel sides to overcome surface tension effects is provided which has feed inlet and exit connected by a feed flow channel; a barrier channel parallel to the feed flow channel, and a filtrate collection channel parallel to the barrier channel so that liquid can flow from the feed flow channel through the barrier channel which is too small to accommodate the particles, into the filtrate collection channel, and from then through a filtrate flow channel to a filtrate exit. Several picoliters of cell-free plasma are recovered from one drop of blood for analysis.

Abstract: The present invention provides a sheath flow module made from a first plate of material having formed therein a laminar fluid flow channel; at least two inlets, each inlet joining the laminar flow channel at a junction, the first inlet junction being wider than the second inlet junction, and an outlet from the flow channel. A second plate, e.g. a transparent cover plate, seals the module and allows for optical measurements. A first inlet allows for introduction of a first fluid into the flow channel. The first fluid is the sheath fluid. A second inlet allows for introduction of a second fluid into the sheath fluid while it is flowing through the flow channel. The second fluid is the center fluid. Because the second inlet junction is narrower than the first inlet junction, the center fluid becomes surrounded on both sides by the sheath fluid. After all fluids have been introduced and sheath flow has been achieved, the depth of the flow channel can be decreased, leading to vertical hydrodynamic focusing.

Abstract: A channel-cell system is provided for detecting the presence and/or measuring the presence of analyte particles in a sample stream comprising: a) a laminar flow channel; b) two inlets in fluid connection with the laminar flow channel for respectively conducting into the laminar flow channel (1) an indicator stream which may comprise an indicator substance which indicates the presence of the analyte particles by a detectable change in property when contacted with the analyte particles, and (2) the sample stream; c) wherein the laminar flow channel has a depth sufficiently small to allow laminar flow of the streams and a length sufficient to allow particles of the analyte to diffuse into the indicator stream to the substantial exclusion of the larger particles in the sample stream to form a detection area; and d) an outlet for conducting the streams out of the laminar flow channel to form a single mixed stream.

Abstract: This invention provides an extraction device and a method for extracting desired particles from a sample stream containing the desired particles. The device has a sample stream inlet, an extraction stream inlet, and an extraction channel in fluid communication with the sample stream inlet and the extraction stream inlet. The extraction channel is for receiving a sample stream from the sample stream inlet in adjacent laminar flow with an extraction stream from the extraction stream inlet. A sequestering material within the extraction channel captures desired particles in the extraction stream. A by-product stream outlet in fluid communication with the extraction channel receives a by-product stream comprising at least a portion of the sample stream form which desired particles have been extracted. A product outlet in fluid communication with the extraction channel receives a product which has the sequestering material and at least a portion of the desired particles.

Abstract: This invention provides a microfabricated extraction system and methods for extracting desired particles from a sample stream containing desired and undesired particles. The sample stream is placed in laminar flow contact with an extraction stream under conditions in which inertial effects are negligible. The contact between the two streams is maintained for a sufficient period of time to allow differential transport of the desired particles from the sample stream into the extraction stream. In a preferred embodiment the differential transport mechanism is diffusion. The extraction system of this invention coupled to a microfabricated diffusion-based mixing device and/or sensing device allows picoliter quantities of fluid to be processed or analyzed on devices no larger than silicon wafers.

Abstract: A microfilter utilizing the principles of tangential flow to prevent clogging, and sloped channel sides to overcome surface tension effects is provided which has feed inlet and exit connected by a feed flow channel, a barrier channel parallel to the feed flow channel, and a filtrate collection channel parallel to the barrier channel so that liquid can flow from the feed flow channel through the barrier channel which is too small to accommodate the particles, into the filtrate collection channel, and from then through a filtrate flow channel to a filtrate exit. Several picoliters of cell-free plasma are recovered from one drop of blood for analysis.

Abstract: This invention provides a valveless method and apparatus for high speed switching of liquid flow between intersecting microchannels. Liquid flow is controlled by manipulating external driving pressures. The switch comprises three intersecting microchannels, each having a liquid reservoir at its nonintersecting end for liquid inlet and outlet. It further includes applying a driving pressure to each reservoir switching the driving pressures. The microswitch of this invention operates to establish a liquid flow from a first channel to a second channel by applying a pressure differential between the first and second reservoirs, while simultaneously preventing flow into the third channel by applying a pressure to the third reservoir which equals the pressure at the junction of the three channels. By switching one or more driving pressures, the flow to the second channel can be stopped and the liquid flow redirected to the third channel.

Abstract: A channel-cell system is provided for detecting the presence and/or measuring the presence of analyte particles in a sample stream comprising: a) a laminar flow channel; b) two inlet means in fluid connection with said laminar flow channel for respectively conducting into said laminar flow channel (1) an indicator stream which may comprise an indicator substance which indicates the presence of said analyte particles by a detectable change in property when contacted with said analyte particles, and (2) said sample stream; c) wherein said laminar flow channel has a depth sufficiently small to allow laminar flow of said streams and a length sufficient to allow particles of said analyte to diffuse into said indicator stream to the substantial exclusion of said larger particles in said sample stream to form a detection area; and d) outlet means for conducting said streams out of said laminar flow channel to form a single mixed stream.