1599results about "Enzyme production/based bioreactors" patented technology

A small diameter flexible electrode designed for subcutaneous in vivo amperometric monitoring of glucose is described. The electrode is designed to allow “one-point” in vivo calibration, i.e., to have zero output current at zero glucose concentration, even in the presence of other electroreactive species of serum or blood. The electrode is preferably three or four-layered, with the layers serially deposited within a recess upon the tip of a polyamide insulated gold wire. A first glucose concentration-to-current transducing layer is overcoated with an electrically insulating and glucose flux limiting layer (second layer) on which, optionally, an immobilized interference-eliminating horseradish peroxidase based film is deposited (third layer). An outer (fourth) layer is biocompatible.

A glucose sensor package system that includes a glucose sensor and a protective package that indicates exposure to temperature changes to indicate proper temperature control. Also covered are methods of transporting and sterilizing the package. In addition, glucose sensors directed to various sizing and positioning of the electrodes on the glucose sensor are covered.

The present invention provides a biointerface membrane for use with an implantable device that interferes with the formation of a barrier cell layer including; a first domain distal to the implantable device wherein the first domain supports tissue attachment and interferes with barrier cell layer formation and a second domain proximal to the implantable device wherein the second domain is resistant to cellular attachment and is impermeable to cells. In addition, the present invention provides sensors including the biointerface membrane, implantable devices including these sensors or biointerface membranes, and methods of monitoring glucose levels in a host utilizing the analyte detection implantable device of the invention. Other implantable devices which include the biointerface membrane of the present invention, such as devices for cell transplantation, drug delivery devices, and electrical signal delivery or measuring devices are also provided.

An electrochemical assay includes a method for determining with great accuracy the time at which an applied sample bridges a gap between the electrodes of an electrochemical cell. The method involves applying a constant small current across the gap, while monitoring the potential difference between the electrodes. The time at which the sample bridges the gap is marked by a sharp drop in the potential. A constant voltage is applied after the sample is detected, and the current and / or charge through the sample is monitored over a period of time. From the measured current or charge, the analyte concentration of interest can be calculated.

A microsphere-based analytic chemistry system and method for making the same is disclosed in which microspheres or particles carrying bioactive agents may be combined randomly or in ordered fashion and dispersed on a substrate to form an array while maintaining the ability to identify the location of bioactive agents and particles within the array using an optically interrogatable, optical signature encoding scheme. A wide variety of modified substrates may be employed which provide either discrete or non-discrete sites for accommodating the microspheres in either random or patterned distributions. The substrates may be constructed from a variety of materials to form either two-dimensional or three-dimensional configurations. In a preferred embodiment, a modified fiber optic bundle or array is employed as a substrate to produce a high density array. The disclosed system and method have utility for detecting target analytes and screening large libraries of bioactive agents.

A small diameter flexible electrode designed for subcutaneous in vivo amperometric monitoring of glucose is described. The electrode is designed to allow “one-point” in vivo calibration, i.e., to have zero output current at zero glucose concentration, even in the presence of other electroreactive species of serum or blood. The electrode is preferably three or four-layered, with the layers serially deposited within a recess upon the tip of a polyamide insulated gold wire. A first glucose concentration-to-current transducing layer is overcoated with an electrically insulating and glucose flux limiting layer (second layer) on which, optionally, an immobilized interference-eliminating horseradish peroxidase based film is deposited (third layer). An outer (fourth) layer is biocompatible.

The present invention provides a biointerface membrane for use with an implantable device that interferes with the formation of a barrier cell layer including; a first domain distal to the implantable device wherein the first domain supports tissue attachment and interferes with barrier cell layer formation and a second domain proximal to the implantable device wherein the second domain is resistant to cellular attachment and is impermeable to cells. In addition, the present invention provides sensors including the biointerface membrane, implantable devices including these sensors or biointerface membranes, and methods of monitoring glucose levels in a host utilizing the analyte detection implantable device of the invention. Other implantable devices which include the biointerface membrane of the present invention, such as devices for cell transplantation, drug delivery devices, and electrical signal delivery or measuring devices are also provided.

The invention provides an implantable membrane for regulating the transport of analytes therethrough that includes a matrix including a first polymer; and a second polymer dispersed throughout the matrix, wherein the second polymer forms a network of microdomains which when hydrated are not observable using photomicroscopy at 400× magnification or less. In one aspect, the homogeneous membrane of the present invention has hydrophilic domains dispersed substantially throughout a hydrophobic matrix to provide an optimum balance between oxygen and glucose transport to an electrochemical glucose sensor.

Methods and microfluidic circuitry for inline injection of nucleic acids for capillary electrophoresis analysis are provided. According to various embodiments, microfabricated structures including affinity-based capture matrixes inline with separation channels are provided. The affinity-based capture matrixes provide inline sample plug formation and injection into a capillary electrophoresis channel. Also provided are methods and apparatuses for a microbead-based inline injection system for DNA sequencing.

Disclosed are methods, devices and systems for biological and chemical sample processing using microfluidic chips. The disclosed microfluidic chips contain at least two detection zones for interacting with pre-selected RNA sequences, DNA sequences, antibodies, or antigens to determine their presence in the sample. Systems are also described comprising a cassette having at least one port and a sample inlet in fluid communication with a detection zone for interacting with pre-selected RNA sequences, DNA sequences, antibodies, or antigens, or mixtures thereof, if present, in a sample. Methods for concurrent testing of at least two of RNA, DNA, antibody, and antigen in a sample are also described, as are methods for testing for pre-selected pathogens and microfluidic methods.

The invention comprises a method of regenerating a biosensor. It involves passing a background flow of fluid without reactive components through the flow passage. At a selected point in time a sample aliquot is injected into said background flow. At a point in time when a signal from said sensor is obtained the flow rate of the background fluid is increased. The invention also comprises a system for continuous monitoring of analytes in a biological fluid, the system having increased life by virtue of inherent regeneration of sensors employed. It comprises a biosensor (26, 30, 32), a sampling device (4) for providing a sample of said biological fluid, and means (10, 15, 18, 24) for passing a flow of a background fluid through said flow passage at selectable flow rates, means (20, 50, 55) for injecting said sample into said flow of background fluid, and means (50, 55) for increasing the flow rate of said combined flow. Means for achieving a washing action at the signal generating portion are provided.

The present invention relates to the field of fluid dynamics. More specifically, this invention relates to methods and apparatus for conducting densely packed, independent chemical reactions in parallel in a substantially two-dimensional array. Accordingly, this invention also focuses on the use of this array for applications such as DNA sequencing, most preferably pyrosequencing, and DNA amplification.

A reagent is suitable for measuring the concentration of an analyte in a hemoglobin-containing biological fluid, such as whole blood. The reagent comprises dehydrogenase enzyme that has specificity for the analyte, NAD, an NAD derivative, pyrrolo-quinoline quinone (PQQ), or a PQQ derivative, a tetrazolium dye precursor, a diaphorase enzyme or an analog thereof, and a nitrite salt. The reagent causes dye formation that is a measure of the analyte concentration. The nitrite salt suppresses interfering dye formation caused non-enzymatically by the hemoglobin. Preferably, the reagent is used in a dry strip for measuring ketone bodies, such as beta-hydroxybutyrate.

The presently disclosed subject matter provides functional perfluoropolyether (PFPE) materials for use in fabricating and utilizing microscale devices, such as a microfluidic device. The functional PFPE materials can be used to adhere layers of PFPE materials to one another or to other substrates to form a microscale device. Further, the presently disclosed subject matter provides a method for functionalizing the interior surface of a microfluidic channel and / or a microtiter well. Also the presently disclosed subject matter provides a method for fabricating a microscale structure through the use of a sacrificial layer of a degradable material.

A disposable biosensor for testing a fluid sample including a laminated strip with a first and second end, a reference electrode embedded in the laminated strip proximate to the first end, at least one working electrode embedded in the laminated strip proximate to the first end and the reference electrode, an open path for receiving a fluid sample beginning from the first end and connecting to a vent spaced from the first end, the open path being sufficiently long to expose the reference electrode and the working electrode to the fluid sample, and conductive contacts located at the second end of the laminated strip. The laminated strip has a base layer with a conductive coating, a reagent holding layer, a channel forming layer and a cover having an inlet notch at the first end. The working electrode contains a reagent having an enzyme.

A biosensor with multi-channel A / D conversion and a method thereof are provided. The present biosensor includes a chip generating a time-dependent analog signal in response to a content of a specific component of a specimen provided thereon, a multi-channel A / D converter, and a microprocessor. The multi-channel A / D converter has multiple channels simultaneously receiving the time-dependent analog signal in each sampling interval to convert the time-dependent analog signal to a set of digital signals. The microprocessor receives the sets of digital signals in a period of sampling time and determines the content of the specific component based on the sets of digital signals. The present biosensor provides a multi-channel A / D conversion for the time-dependent analog signal to improve the resolution of the determination of the content of the specific component.

Assay cartridges are described that have purification, reaction, and detection zones and other fluidic components which can include sample chambers, waste chambers, conduits, vents, reagent chambers, reconstitution chambers and the like. The assay cartridges are used to conduct multiplexed nucleic acid measurements. Also described are kits including such cartridges, methods of using the same, and a reader configured to analyze an assay conducted using an assay cartridge.

The present invention provides a method, device and a computer program for haplotyping single cells, such that a sample taken from a pregnant female, without directly sampling the fetus, provides the ability to non-invasively determine the fetal genome. The method can be performed by determining the parental and inherited haplotypes, or can be performed merely on the basis of the mother's genetic information, obtained preferably in a blood or serum sample. The novel device allows for sequence analysis of single chromosomes from a single cell, preferably by partitioning single chromosomes from a metaphase cell into long, thin channels where a sequence analysis can be performed.

Multiwell droplet actuators, systems and methods are provided. According to one embodiment, a substrate is provided and comprises: (a) one or more input ports for introduction of one or more reagents and / or samples; (b) a regular array of processing wells; and (c) a network of droplet transport pathways comprising pathways that provide direct or indirect droplet transport from each of the input ports to each of the one or more processing wells. Varying droplet actuators and systems related thereto are also provided.

An object of the invention is to provide a method for delivery of macromolecules into biological cells, such as Langerhans cells (22) in the epidermis (20) of a patient, which includes the steps of coating electodes (16) in an electrode assembly (12) with solid phase macromolecules to be delivered, such as a DNA, and / or RNA vaccine or a protein-based vaccine, attaching the electrode assembly (12) having the coated electrodes (16) to an electrode assembly holder (13), providing a waveform generator (15), establishing electrically conductive pathways between the electrodes (16), and the waveform generator (15), locating the electrodes (16) such that the biological cells are situated therebetween, such as by penetrating the needle electrode (16) into the epidermis (20) above the epidermal basal lamina, and providing pulse waveform from the waveform generator (15) to the electrodes (16), such that macromolecule on the electrodes (16) is driven off of the electrodes (16), and delivered into the biological cells, such as the Langerhans cells (22).

Since conventional DNA sequence analyzing technologies are based on the fundamental principle of fluorescent detection, expensive, complex optical systems and laser sources have been necessary.A field-effect device for gene detection of the present invention analyzes a base sequence by immobilizing a single-strand nucleic acid probe at a gate portion, inducing hybridization at the gate portion to form a double-stranded DNA, inducing elongation reaction by adding a DNA polymerase and one of the substrates, and measuring the electrical characteristic of the field-effect device caused by elongation reaction.Since the elongation reaction of one base induced at the gate portion can be directly converted to an electrical signal, expensive lasers or complex optical systems are not needed. Thus, a small gene polymorphism detection system that can conduct measurement at high precision can be provided.

A self-contained device is described that integrates nucleic acid extraction, specific target amplification and detection into a single device. This integration permits rapid and accurate nucleic acid sequence detection. The invention may be used, for example, in the screening for nucleic acid sequences which may be indicative of genetic defects or contagious diseases, as well as for monitoring efficacy in the treatment of contagious diseases.

The invention relates to devices and methods for nanopore sequencing. The invention includes compositions and methods of nucleic acid sequencing using a single polymerase enzyme complex comprising a polymerase enzyme and a template nucleic acid attached proximal to a nanopore, and nucleotide analogs in solution comprising charge blockade label that are attached to the polyphosphate portion of the nucleotide analog such that the charge blockade labels are cleaved when the nucleotide analog is incorporated into a growing nucleic acid and the charge blockade label is detected by the nanopore to determine the presence and identity of the incorporated nucleotide and thereby determine the sequence of a template nucleic acid.

The present invention relates to methods for producing carbon-based molded bodies. In particular, the present invention relates to methods for producing porous carbon-based molded bodies by carbonizing organic polymer materials mixed with non-polymeric fillers and subsequently dissolving the fillers out from the carbonized molded bodies. The present invention further relates to methods for producing porous carbon-based molded bodies by carbonizing organic polymer materials mixed with non-polymeric fillers which are substantially completely decomposed during the carbonization. The present invention also relates to a method for producing porous carbon-based molded bodies by carbonizing organic polymer materials, the carbon-based molded bodies being partially oxidized following carbonization so as to produce pores. In addition, the present invention relates to porous molded bodies produced according to one of said methods and the use thereof, especially as cell culture carriers and / or culture systems.

Methods and devices for determining the concentration of a constituent in a physiological sample are provided. The blood sample is introduced into a test strip with portions of the blood sample being directed to both a first capillary and a second capillary. The first capillary configured to electrochemically determine a concentration of a first analyte in a blood sample by measuring a signal across a set of electrodes. The second capillary is configured to determine a hematocrit value of the blood sample by measuring a signal across a second set of electrodes.

Electrochemical test strip cards that can be singulated to produce electrochemical test strips are provided. The electrochemical test cards are made up of two or more electrochemical test strip precursors, where each precursor is characterized by the presence of a dry reagent housing reaction chamber bounded by opposing electrodes. In gaseous communication with each reaction chamber of the card is an integrated desiccant. Also provided are methods of using the subject electrochemical test strips cards, as well as kits that include the same. The subject test strips and cards find use in the detection / concentration determination of a number of different analytes, including glucose.

A device comprising an array of molecules immobilised on a solid surface is disclosed, wherein the array has a surface density which allows each molecule to be individually resolved, e.g. by optical microscopy. Therefore, the arrays of the present invention consist of single molecules that are more spatially distinct than the arrays of the prior art.