Abstract: A system is provided for stimulating one or more cells, wherein the stimulation is sub-threshold and may alter a transmembrane potential of the one or more cells. For some populations of cells it may be possible to affect the transmembrane potential to gain a therapeutic benefit. Cells of the sino-atrial node spontaneously depolarize predominantly due to the slow depolarization of transmembrane potential. The present system may provide sino-atrial cells with a local field stimulation that while not eliciting an action potential may nonetheless alter local transmembrane potential. Such alteration of transmembrane potential may permit an increase or decrease in a rate of depolarization, and hence modify heart rate.

Abstract: An opening is formed in a cell using laser radiation. A Bessel beam is formed using the laser radiation and the Bessel beam is directed onto the cell to form an opening. The guiding of material towards the opening may be involved using optical trapping/manipulation. The material may change cellular function or analyse cell behaviour. Both pulsed laser radiation and continuous wave radiation may be formed using the same laser.

Abstract: A method for detecting the expression of a polypeptide in cells and for detecting the interaction between a polypeptide and cells, ex vivo or in vitro, wherein the polypeptide is selected from the group consisting of: a peptide comprising the cyt domain of the envelope protein of the human endogenous retrovirus, HERV-W; a peptide comprising amino acids 448-538 of SEQ ID NO: 1; and a peptide comprising a sequence having, for any series of 20 amino acids, at least 80% identity with amino acids 448-538 of SEQ ID NO: 1. Detection is established by the fusogenic power of the polypeptide, which is demonstrated by syncytia formation.

Abstract: A device and methods for monitoring status of at least one cell, wherein the cell has a membrane forming a substantially enclosed structure and defining an intracellular space therein. In one embodiment of the present invention, the device includes a first substrate having a first surface and an opposite second surface, a second substrate supported by the first substrate, the second substrate having a first surface, an opposite second surface, a body portion between the first surface and the second surface, a first side surface and an opposite second side surface, wherein the body portion defines a first passage between the first side surface and the second side surface and an opening on the first surface of the second substrate and in fluid communication with the first passage, and sidewalls positioned above the first surface of the second substrate.

Abstract: The invention provides methods for purifying one or more cells based on the level of one or more products secreted by the cells.

Abstract: An oocyte recording chamber for electrophysiological measurements. The recording chamber includes a base and a cover attached to the base. The cover and the base define a chamber having a size sufficient to accommodate an oocyte. The recording chamber includes a first electrode and a second electrode that are positioned so that the tips of the electrodes penetrate the membrane of the oocyte when the cover is fastened to the base. The recording chamber also includes a third electrode and a fourth electrode exposed to the chamber and used as ground electrodes.

Abstract: An apparatus for electrically contacting biological cells suspended in a liquid has a substrate having at least one opening and an electrode for electrically contacting a cell immobilized above the opening. A contact unit with a contact tip is arranged below said opening. A top end of the contact tip projects into the opening in such a way that it comes to bear against a cell membrane of the immobilized cell. The contact tip has a contact channel which ends at its top end. A hydrodynamic low pressure can be exerted upon the cell membrane via the contact channel, and the electrode is electrically connected to the contact channel. In a method for electrically contacting biological cells suspended in a liquid, a cell is immobilized above an opening provided in a substrate, and the immobilized cell is contacted via at least one electrode. For contacting the immobilized cell, a hydrodynamic low pressure is generated acting on a cell membrane through a contact tip projecting into the opening.

Abstract: Methods for increasing lipolysis in a cell are described herein. Such methods comprise the application of an electrical current to a cell. In an embodiment, the application of the electrical current does not substantially alter the viability of such cell and/or preserves the viability of such cell. In an embodiment, such cell is an adipocyte. Corresponding uses and packages are also described.

Abstract: A method for identifying a selective persistent Na+ channel blocker by measuring the ability of the blocker to reduce or inhibit a persistent Na+ current to a greater degree than a transient Na+ current. Aspects of the present method provide Na+ depletion/repletion methods for identifying a selective blocker of a persistent Na+ channel, hyperpolarization methods for identifying a blocker of a persistent Na+ channel, and Na/K ATPase pump inhibitor methods for identifying a selective blocker of a persistent Na+ channel.

Abstract: We disclose methods of sorting or separating mixtures of living cells (e.g., eukaryotic, prokaryotic, mammalian, pathogenic, bacterial, viral, etc.). We perform our methods by activating cell-selective photophoric labels, which photosensitize and chemically reduce a photosensitive metal compound to form metal grains, particles or crystals. The metal adheres to the cells and forms the basis for sorting or separating different cell types. Photophoric labels may include chemiluminescent agents such as peroxidase enzymes activated with peroxidase substrates capable of luminescence. Photosensitive metal compounds may be present in a light-sensitive matrix or emulsion containing photosensitizable metal compounds, which form metal grains, particles or crystals upon exposure to a developer solution. Developer solutions are formulated to substantially allow living cells to remain viable after exposure to the developing solution.

Abstract: Disclosed are methods relating to cell membrane fragments associated with microbeads, so that the characteristics of the cells the fragments originated from can be determined. The fragments can be oriented with what was the outer surface of the cell membrane facing outwardly, so that the antigens associated with the membrane can be contacted with ligands (including antibodies) to antigens in the membranes which would be accessible to antibodies in vivo. The system is useful, inter alia, for detection of panel reactive antibodies in donor serum, as well as detection of other cell membrane antigens; or quantitation of particular cell membrane antigens.

Abstract: A method and system for electrically wounding and/or monitoring cell activity in vitro. The invention comprises methods and systems for wounding and/or monitoring cells that place a cell culture on a well that has an exposed electrode. The cell culture can then be wounded and/or monitored using the electrode.

Abstract: An electronic sensor is provided for detecting the presence of one or more targets of interest in a sample. The sensor preferably comprises a special type of field effect transistor in which conductance is enhanced by target binding to recognition elements in the active region. An array of sensors may be formed to analyze a sample for multiple targets. The sensor may be used, for example, to detect the presence of pathogens, polypeptides, nucleic acids, toxins and other biochemical and chemical agents. The sensor is useful in a wide variety of applications including medical diagnostics, agriculture, public health, environmental monitoring and biomedical research.

Abstract: Systems for positioning and/or analyzing samples such as cells, vesicles, cellular organelles, and fragments, derivatives, and mixtures thereof, for electrical and/or optical analysis, especially relating to the presence and/or activity of ion channels.

Abstract: The present invention includes devices, systems, and methods for assaying cells using cell-substrate impedance monitoring. In one aspect, the invention provides cell-substrate impedance monitoring devices that comprise electrode arrays on a nonconducting substrate, in which each of the arrays has an approximately uniform electrode resistance across the entire array. In another aspect, the invention provides cell-substrate monitoring systems comprising one or more cell-substrate monitoring devices comprising multiple wells each having an electrode array, an impedance analyzer, a device station that connects arrays of individual wells to the impedance analyzer, and software for controlling the device station and impedance analyzer. In another aspect, the invention provides cellular assays that use impedance monitoring to detect changes in cell behavior or state. In some preferred aspects, the assays are designed to investigate the affects of compounds on cells, such as cytotoxicity assays.

Abstract: This invention provides a method for screening large numbers of individual cells or colonies of cells using scanning microscopy coupled with fluorescence lifetime measurement and analysis, using time-correlated single photon counting. This invention further provides an automated method for selecting cells that exhibit desired characteristics. The method uses the scanning microscope system to focus a laser beam onto a surface upon which cells are immobilized on the timescale of the procedure. The cells that are illuminated in this way are killed or their growth is inhibited. The focused laser beam is scanned across the surface and turned on and off during the scanning process such that only non-irradiated cells survive, resulting in a patterned cell growth This invention further provides a computer-controlled projection device, such as a micro-mirror array or a liquid crystal display system, which is sued to project an image onto the cells.

Abstract: An improved system for cellular surgery which includes a laser for producing a laser beam, and confocal optics for scanning and focusing the laser beam in tissue and generating confocal images of the tissue in accordance with returned light from the tissue. The confocal images are visualized on a display. The system includes a controller for enabling the operator to select one or more cells of the tissue in the displayed confocal images for surgical treatment. The controller operates the laser and confocal optics in a first mode to treat the tissue when the confocal optics focus the laser beam at least one region associated with the selected cells in the tissue, but at all other times operates the laser and confocal optics in a second mode which does not damage the tissue.

Abstract: High frequency interfacing to biochemical membranes, such as supported bilayers and cell membranes, is carried out by supporting a biochemical membrane on a support surface while allowing access to the surface of the membrane through an opening in the support. A sharp tipped probe is positioned adjacent to the exposed surface of the membrane. The probe may have an inner core tip and a coaxial shield around the core tip that is electrically insulated therefrom. Radio frequency power is supplied to the probe to apply a localized radio frequency field to the membrane adjacent to the probe. Transport and binding events at the membrane are detected by changes in the field transmitted through the membrane and received by a receiving probe, or reflected from the membrane and received by the transmitting probe, and coupled therefrom to a detector for detection.

Abstract: A method is described for treating biological cells and/or their cell components with electrical fields in a reaction medium, in which an inhibitor is added to the reaction medium to counteract the action of enzymes that break down protein.

Abstract: This invention relates generally to the field of cell separation or isolation. In particular, the invention provides a method for separating cells, which method comprises: a) selectively staining cells to be separated with a dye so that there is a sufficient difference in a separable property of differentially stained cells; and b) separating said differentially stained cells via said separable property. Preferably, the separable property is dielectrophoretic property of the differentially stained cells and the differentially stained cells are separated or isolated via dielectrophoresis. Methods for separating various types of cells in blood samples are also provided. Centrifuge tubes useful in density gradient centrifugation and dielectrophoresis isolation devices useful for separating or isolating various types of cells are further provided.

Abstract: A method is presented for killing a first population of cells within a mixture of viable cells by providing the mixture of viable cells, contacting the cells with a label, illuminating a portion of the mixture, capturing an image of multiple cells in the illuminated portion of the mixture, determining at least two dimensional coordinates of one or more cells of the first population of cells using the first captured image, and applying a lethal dose of energy to said dimensional coordinates of the one or more cells at a first focal plane.

Abstract: The present invention relates to the signalling pathways connecting DNA damage, such as that induced by ionizing radiation or alkylating agents, and phosphorylation by tyrosine kinases.

Abstract: An improved method for the design and development of high performance hybrid devices having biological and nonbiological components. A figure of merit is developed for the biological component or components. The component is subjected to various environmental variables as it or its biological source organism is grown. The biological component is force adapted to cause its figure of merit to reach a goal or an acceptable measure. The biological component is used in hybrid constructs that may be nanostructures, given the small size of the biological parts. In one specific embodiment, force-adapted chlorosomes of C. aurantiacus enhance performance of a silicon photovoltaic cell. The bacteria, Chloroflexus aurantiacus (C. aurantiacus), strain J-10-fl, has the A.T.C.C. designation number 29366, having been deposited in July, 1976.

Abstract: A method for identifying a Na+ channel blocker, including providing a cell containing a Na+ channel, demonstrating both a transient and a persistent current. The cell includes a potassium (K+) channel and a Na/K ATPase (Na+ pump). A fluorescent dye is disposed into the well. The fluorescent dye is sensitive to change in cell membrane potential in order to enable optical measurement of cell membrane potential. A Na+ channel blocker, to be identified, is added to the well and a stimulating current is passed through the cell in an amount sufficient to generate an action potential before and after the addition of the Na+ channel blocker. Thereafter, a change in cell membrane potential is optically measured.

Abstract: Nucleic acid compositions encoding non-aggregating chromo/fluoroproteins and mutants thereof, as well as the encoded proteins, are provided. The proteins of interest are polypeptides that are non-aggregating colored and/or fluorescent proteins, where the non-aggregating feature arises from the modulation of residues in the N-terminus of the protein and the chromo and/or fluorescent feature arises from the interaction of two or more residues of the protein. Also provided are fragments of the subject nucleic acids and the peptides encoded thereby, as well as antibodies to the subject proteins and transgenic cells and organisms. The subject protein and nucleic acid compositions find use in a variety of different applications. Finally, kits for use in such applications, e.g., that include the subject nucleic acid compositions, are provided.

Abstract: The present invention provides a device and method for determining the adequacy of squamous (ectocervical) cells, columnar (endocervical) cells, neutrophils, and noncellular material in a liquid based cytology specimen. The invention first analyzes a liquid based cytology specimen using light scatter to create a light scatter characteristic representing a predetermined cell. Next the invention determines the presence of squamous (ectocervical) cells versus columnar (endocervical) cells versus neutrophils versus noncellular material using the results of the light scatter. The light scatter characteristic that may be used may be forward light scatter, side light scatter, or both side and forward light scatter.

Abstract: Immunoassay methods and apparatus are provided which utilize flow cytometry, coated latex microspheres, and fluorochrome labeled antibodies, to simultaneously detect the presence and amount of one or more analytes in a sample. By combining FALS and fluorescence, it is practical to use beads of several different sizes, colors or shapes, each bead coated with a different analyte, for the simultaneous detection of one or more analytes and of cell components such as platelets in a sample.

Abstract: A polymeric material such as PDMS is molded into an electrode structure containing a micron-size aperture for receiving and forming a giga-ohm seal with a biological membrane. One end of a tube is filled with uncured polymeric material and pressed against a support surface to prevent drainage. A conventional micropipette having a size suitable for sliding through the tube is introduced, tip first, into the tube and is allowed to fall through the polymeric material and rest against the support surface. The assembly is heated to cure the polymer and the micropipette is removed from the tube, thereby leaving a polymeric plug at the end of the tube with an aperture suitable in shape and size for patch-clamp giga-ohm seal electrode applications. A multi-well tray with a polymeric electrode plug in each well is constructed using the same approach.

Abstract: The invention relates to a method for selectively releasing an agent loaded into a red blood cell, comprising electrosensitizing the red blood cell by application of an electric field and subsequently disrupting the cell selectively using ultrasound.

Abstract: A perfusion-chamber structure includes a chamber plate with an extracellular compartment, a partition plate with an electrode aperture, and a foundation plate with an intracellular compartment. A gap between the chamber plate and the partition plate produces a channel for applying suction that draws extracellular solution from the extracellular compartment and facilitates the movement and positioning of a test cell over the electrode aperture. The positioning procedure for the test cell is accompanied by a slight positive pressure applied to the intracellular solution in the intracellular compartment of the perfusion chamber to cause upward fluid flow through the electrode aperture. When the cell is positioned over the electrode aperture, the positive pressure on the intracellular fluid is reversed to suction and the cell is seated thereby to form the seal.

Abstract: The invention relates to a measuring device which permits a very simple positioning of cells and vesicles respective of cell membranes on planar carriers. The invention also relates to a corresponding highly efficient method for the positioning and electric characterization of such membranes with a consistently high signal-to-noise ratio. In addition, statements concerning interactions of substances with lipid membranes respective of materials bonded thereon or therein respective of signal transduction mechanisms connected thereto are possible.

Abstract: The present invention relates to ionic electrodes, particularly microelectrodes and electrode arrays, and also relates to fabrication methods for such electrodes. In particular, the present invention relates to planar polymer electrodes for making patch clamp measurements of ionic currents through biological membranes, such as the plasma membranes of living cells. The electrodes of the present invention are useful for measuring individual and multisite cell membrane currents and voltages, as well as in high-throughput screening procedures.

Abstract: The invention concerns a device comprising a support (11) in the thickness of which is produced a supply chamber (12) with an inlet duct (13) for nutrient liquid and a discharge duct (14) for said liquid. A capsule (22) capable of receiving organic cells is provided on the support (11). The supply chamber (12) and the support (11) are separated by a porous membrane (16) comprising an array of electrodes (17) arranged so as to be in contact with different zones of the group of cells, thereby enabling their electrophysiological activity to be analyzed. The device enables to increase the life span of cells and to carry out analyses simply and without affecting the cell organization.

Abstract: The object of the invention is to provide a method and apparatus for treating membrane-containing material with electrical fields, in vitro, and with an added treating substance. With the method, a plurality of electrodes are arrayed around the material to be treated and are connected to outputs of an electrode selection apparatus. Inputs of the electrode selection apparatus are connected to outputs of a pulse sequence generator. A treating substance is added to the membrane-containing material. Electrical pulses are applied to the electrode selection apparatus and are routed through the electrode selection apparatus in a predetermined, computer-controlled sequence to selected electrodes in the array of electrodes, whereby the membrane-containing material is treated with the added treating substance and with electrical fields. The routing of applied pulses through the electrode selection apparatus to selected electrodes can be done in an enormous number of ways.

Abstract: Delivery of metal particles to living tissue, then applying external energy that interacts with the metal particles, is found to selectively increase the energy deposition and interaction surrounding the metal particles. The method is useful to improve treatment of various conditions, since targeted cells may be selectively altered or killed. Metal particles are also loaded into cells or membrane vesicles by placing metal seed particles into the cells or vesicles, then chemically depositing additional metal on the metal seed particles. The metal particles are useful to improve imaging and therapies by their interaction with externally applied energy.

Abstract: A method and apparatus is disclosed for selectively identifying, and targeting with an energy beam, specific cells within a mixed cell population, for the purpose of inducing a response in the targeted cells. Two or more fluorescent labels can be attached to the targeted cells, and distinguished from one another by a color camera. By use of this system, one can monitor and affect cells having a desired phenotype. For example, targeted cells can not only be inactivated by an energy beam, but can also be monitored through fluorescent labeling for changes in cell morphology, ion transport or other cellular functions.

Abstract: Efficient cell lysis in small samples, i.e., samples less than one milliliter, is achieved by exposing the sample to microwave radiation in the frequency range of 18 to 26 GHz. The sample containing cells is supported in a wave-guide cavity, and a microwave source provides microwave radiation to the input port of the wave-guide cavity. A computer controls the frequency and source power level of the microwave radiation produced by the microwave source. The computer also monitors the input power level of the microwave radiation at the input port by means of an input power measuring instrument, the output power level at the output port by means of an output power measuring instrument, and the temperature of the sample by means of a thermocouple. In this way, the computer can control the operating parameters to achieve efficient cell lysis.

Abstract: A separation and release process for purifying biological material on a micro separation column includes release of the biological material from magnetic carriers and elution from the micro separation column while the magnetic carriers are still magnetically retained by a matrix of ferromagnetic particles inside the micro separation column.

Abstract: Methods and compositions are provided for determining the potential of a membrane. In one aspect, the method comprises: (a) introducing a first reagent comprising a hydrophobic fluorescent ion capable of redistributing from a first face of the membrane to a second face of the membrane in response to changes in the potential of the membrane, as described by the Nernst equation, (b) introducing a second reagent which labels the first face or the second face of the membrane, which second reagent comprises a chromophore capable of undergoing energy transfer by either (i) donating excited state energy to the fluorescent ion, or (ii) accepting excited state energy from the fluorescent ion, (c) exposing the membrane to radiation; (d) measuring energy transfer between the fluorescent ion and the second reagent, and (e) relating the energy transfer to the membrane potential. Energy transfer is typically measured by fluorescence resonance energy transfer.

Abstract: Cysteine-depleted CTL epitopes can elicit a stronger or more specific CTL response than the native, cysteine-containing CTL epitope of a disease associated antigen.

Abstract: Microfluidic systems and methods are disclosed which are adapted to transport and lyse cellular components of a test sample for analysis. The disclosed microfluidic systems and methods, which employ an electric field to rupture the cell membrane, cause unusually rapid lysis, thereby minimizing continued cellular activity and resulting in greater accuracy of analysis of cell processes.

Abstract: Disclosed is an improved process for irradiating cell-containing compositions, especially, red cell-containing compositions, wherein vitamin E or a derivative thereof is added to the cell-containing composition prior to, during or after such irradiation. Addition of vitamin E or a derivative thereof is protective of cells in such compositions, but not of virus. Cells irradiated using the inventive process show a reduced leakage of K+ from cells and also a reduced loss of negative charges from the cell membrane compared to cells subjected to the similar process wherein vitamin E or a derivative thereof are not used. In addition, red blood cells sterilized by this process are better preserved during storage and their life-time in the circulation in vivo is greatly enhanced.

Abstract: The present invention relates to the signalling pathways connecting DNA damage, such as that induced by ionizing radiation or alkylating agents, and phosphorylation by tyrosine kinases.

Abstract: A process is provided for the intracellular manipulation of a biological cell (3) which is positioned adhering to a support area (5) in a culture medium (2). Inside the support area (5) for the cell (3) an opening into the membrane of the cell (3) is created spaced from its support edge. The edge of the cell membrane surrounding the opening, adhering to the support area (5), thus seals off the cell fluid situated in the interior of the cell (3) from the culture medium (2) and insulates the cell fluid against the culture medium (2). The interior of the cell (3) is manipulated through the opening. An apparatus for implementing the process is also provided, including an object carrier (4) with a support area (5) for adhering the cell and a poration tool (6) for creating the opening in the cell membrane. The poration tool (6) may be any of various chemical, mechanical and/or electrical devices.

Abstract: A micro column system is provided for high gradient magnetic field separation of macromolecules and/or cells. The system provides fast kinetics and high efficiency as well as the purity and simplicity of a column separation. A yoke provides a magnetic field to a plurality of micro columns. A separation and release process for purifying biological material on the column includes release of the biological material from magnetic particles and elution from the column while the magnetic particles are still magnetically retained by the matrix inside the column.

Abstract: Compositions for monitoring transmembrane potential across cellular membranes. The compositions typically comprise a cell having a plasma membrane that comprises a first leaflet and a second leaflet, the membrane comprising first and second membrane associated components which, when placed adjacent each other either produce or quench a fluorescent signal, wherein. The first membrane associated component translocates from a first leaflet of the membrane to a second leaflet of the membrane in response to an electrical potential gradient across the membrane, the first membrane associated component being selected from a non-fluorescent cationic fluorescence quencher a non-fluorescent anionic fluorescence quencher and a cationic fluorophore.

Abstract: A cosmetic method of treatment of dermatological conditions, particularly portwine stains, tattoos or psoriasis, which includes irradiating the affected area with an incoherent high intensity non-laser light beam having an intensity greater than 0.075 watts per square centimeter, the light beam having only a bandwidth in the range 0 to 30 nm. The method can include delivery of the light beam by optic fiber bundle by pulsed or non-pulsed light. The method can also include the introduction of a drug into the body undergoing the treatment, wherein the drug is activated by light of a particular wavelength.

Abstract: The recovery yields of intact plasmids from bacterial cells mechanically disrupted by various methods were measured. Bacterial cell disruption through bead milling and microfluidization were found to achieve the greatest recovery of intact plasmid. Other methods resulted in substantial DNA plasmid degradation.

Abstract: a method is provided for detecting a presence of HIV virus in a sample comprising: taking a culture of recombinant cells which (a) are capable of cell division, (b) express CD4 receptor and one or more additional cell surface receptors necessary to allow the HIV virus to infect, (c) enable the HIV virus to replicate and infect the noninfected cells in the cell culture, and (d) comprise a reporter sequence introduced into the recombinant cells comprising a reporter gene whose expression is regulated by a protein specific to HIV viruses which is expressed from a genome of an HIV virus upon infection of the recombinant cell by the HIV virus; contacting the cell culture with a sample to be analyzed for the presence of HIV virus in the sample; and detecting a change in a level of expression of the reporter gene in cells in the recombinant cell culture.

Abstract: The present invention discloses positive control material for nucleic acid amplification based detection of microorganisms in biological samples. The control material comprises purified microorganism that is rendered non-infectious but is amenable to nucleic acid amplification. Also disclosed is a process for making and using the control material.