Abstract:
The invention provides assay methods and kits that in general measure the level of a first analyte in a sample reduced by the level of a second analyte present in the same sample. In one embodiment, where levels of a first analyte from a first source is desirably determined and first analyte in the sample released from a second source is accompanied by proportional co-release of a second analyte, the assay identifies the level of first analyte released only from the first source. For analytes within bodily fluids, the assay can differentiate between elevated levels of analyte specific to the particular physiological or pathological state and elevated levels not specific to the particular state, providing single tests with diagnostic utility.
Abstract:
A microactuator device (12) includes a base (20) with at least one electrode pad (24) and a permeation membrane (18). Permeation membrane (18) is typically a water-permeable membrane that is able to deform by applying an electric charge to the electrode pad (24). The actuator device (12) can be incorporated into valve assembly (10) to open and close the valve. The valve assembly can have a reciprocating valve member (146) operated by the deforming of the water-permeable member. Alternatively, the valve assembly can have an opening (46) positioned to cooperate with the water-permeable membrane (18) so that the deformation of the membrane closes the opening.
Abstract:
Electronically addressable microchips having covalently bound permeation layers and methods of making such covalently bonded permeation layers to microchips are provided. The covalent bonding is derived from combining the use of electrodes with silane derivatives. Such chemistry provides the ability to apply an electronic bias to the electrodes of the microchip while preventing permeation layer delaminating from the electrode surface.
Abstract:
The present invention pertains to a method of, and a device created by, depositing an inorganic permeation layer on a micro-electronic device for molecular biological reactions. The permeation layer is preferably sol-gel. The sol-gel permeation layer can be created with pre-defined porosity, pore size distribution, pore morphology, and surface area. The sol-gel permeation layer may also function as the attachment layer of the micro-electric device.
Abstract:
The invention provides for a method for electronically controlled hybridization of DNA from a solution containing specific binding and non-specific binding DNA sequences to a binding location.
Abstract:
The following inventions relate to discoveries concerning the various parameters, electrolytes (buffers), and other conditions which improve or optimize the speed of DNA transport, the efficiency of DNA hybridization reactions, and the overall hybridization specificity in microelectronic chips and devices. In particular, this invention relates to the discovery that low conductance zwitterionic buffer solutions, especially those containing the amino acid Histidine prepared at concentrations of ∩50 mM and at or near the pI (isoelectric point ∩pH 7.47), provide optimal conditions for both rapid electrophoretic DNA transport and efficient hybridization reactions. Hybridization efficiencies of at least a factor of 10 relative to the next best known buffer, Cysteine, are achieved. Test data demonstrate an approximately 50,000 fold increase in hybridization efficiency compared to Cysteine.
Abstract:
A rapid assay for single nucleotide polymorphism (SNP) detection that utilizes electronic circuitry on silicon microchips is disclosed. The method provides accurate discrimination of amplified DNA samples following electronic assisted transport, concentration, and attachment of DNA to selected electrodes (test sites). The test sites make up organized arrays of samples that are distinguished by using internal controls of dual labeled reporters comprising wild-type and mismatched sequences to validate the SNP genotype. This method has been used to discriminate the complex quadra-allelic SNP of mannose binding protein.
Abstract:
The present invention comprises devices and methods for performing channel-less separation of cell particles by dielectrophoresis, DC high voltage-pulsed electronic lysis of separated cells, separation of desired components from crude mixtures such as cell lysates, and/or enzymatic reaction of such lysates, all of which can be conducted on a single bioelectronic chip. A preferred embodiment of the present invention comprises a cartridge (10) including a microfabricated silicon chip (12) on a printed circuit board (14) and a flow cell (16) mounted to the chip (12) to form a flow chamber. The cartridge (10) also includes output pins (22) for electronically connecting the cartridge (10) to an electronic controller. The chip (12) includes a plurality of circular microelectrodes (24) which are preferably coated with a protective permeation layer which prevents direct contact between any electrode and a sample introduced into the flow chamber. The permeation layer also helps to reduce cell adhesion at field minima, and enables immobilization of specific antibodies for specific cell capture. Specific cells from various cell mixtures were separated, lysed, and enzymatically digested on the chip.