Abstract:
An immobilizing device for biological material comprises a rigid support (12) carrying a substrate layer (20, 20′) of polymer having biological immobilizing properties, e.g. for amino and nucleic acids. Substantially solid ultra-thin substrate layers (20′) having a thickness less than about 5 micron, preferably between about 0.1 and 0.5 micron, and micro-porous, ultra-thin substrate layers (20′) having a thickness less than about 5 micron, preferably less than 3 micron, 2 or 1 micron are shown, which may be segmented by isolating moats M. The substrate layer is on a microscope slide (302), round disc (122), bio-cassette, at the bottom of a well of a multiwell plate, and as a coating inside a tube. Fluorescence or luminescence intensity and geometric calibration spots (420) are shown. Reading is enhanced by the intensity calibration spots. (420) to enable normalization of readings under uneven illumination conditions, as when reading by dark field, side illumination mode. The reference spots are shown being printed simultaneously with printing an array of biological spots or with the same equipment. Methods of forming layers of the device include controlled drawing from a bath of coating composition and drying, and spinning of C-D shaped substrates. Post-forming treatment is shown by corona treatment and radiation. Adherent metal oxides (14), silica-based materials and other materials are used to unite layers of the composite. In multi-well plates the oxide promotes joining of a bottom plate (95, 95′) and upper, well-defining structure (94) of dissimilar material. The oxides (14) also provide beneficial opacity to prevent light entering the glass support, for applying potential to the substrate, etc.
Abstract:
Operation of an electronic circuit is simulated. A plurality of data points representing operation of the electronic circuit at a plurality of operating conditions is obtained. A boundary that encompasses the plurality of data points is constructed. The boundary defines a bounded domain of operating conditions for the electronic circuit. A model function representing operation of the electronic circuit within and without the bounded domain of operating conditions is produced. The model function is determined within the bounded domain of operating conditions. The model function is extended outside the bounded domain so that all first order partial derivatives of the model function for operating conditions located outside and not near the boundary are large and positive. The model function is utilized to simulate operation of the electronic circuit.
Abstract:
The present invention includes a method for generating a model of a circuit having an input port and an output port. The method determines an amplitude for current leaving the output port at a frequency ωk when a signal that includes a carrier at ωj modulated by a signal Vj(t) is input to the input port, wherein ωk is a harmonic of ωj. The determined amplitude is used to determine values for a set of constants, ak, such that a function fk(V,ak) provides an estimate of the current, Ik(t), leaving the output port at a frequency ωk when a signal having the form V ( t ) = Re ∑ k = 1 , H V k ( t ) exp ( jω k t ) is input to the input port. Here Vk(t) is a component of a set of values V. The fk(V,ak) are used to provide a simulator component adapted for use in a circuit simulator.
Abstract:
Methods and apparatus for depositing a high density biological or chemical array onto a solid support. Specifically, the apparatus is made up of a plurality of open ended channels collectively forming a matrix. The matrix has been redrawn and cut such that the pitch of the channels on the loading end is larger than the pitch of the channels on the liquid delivery end. The upper portion of each channel serves as a reservoir, while the opposing end, which has been formed by the redrawing process, is diametrically sized such that liquid in the reservoir is retained by capillary pressure at the delivery end. At any point along the height of the capillary reservoir device, all cross-sectional dimensions and areas are uniformly reduced. In other words, the on-center orientation of any two channels, also referred to as the pitch between 2 channels, measured as a function of the diameter of any cross section, is constant throughout the structure. The liquid within the channels is either printed directly from the tool onto a substrate or transferred to a substrate by a typographical pin plate. In another embodiment, the device may be used in transferring sample between multiwell plates of different well density.
Abstract:
A laboratory research tool for conducting a variety of procedures including cell and tissue culture techniques includes a multi-well cluster plate, a filter plate that has one or more filter wells that extend into the wells of the cluster plate, a cover and a reservoir that can be used with auxiliary equipment designed for use with standard 96-well format cluster plates. The system allows multiple tissue samples to be grown and manipulated simultaneously.
Abstract:
A tissue or cell growth device is described for placement within a well of a cluster dish. The device has a cell or tissue retention element detachably attached to a hanger. The hanger preferably has openings allowing access to the well without removal of the member and is capable of positioning the cell or tissue retention element a preselected distance relative to the hanger. Also described are various embodiments of the device having differently shaped hangers and the combination of the device and a cluster dish.
Abstract:
A filter strip and composite assemblies for filtering microliter quantities of fluids wherein a linear array of wells having open top and bottom ends are connected by frangible webs in spaced-apart relation with discrete filter membranes closing the bottom ends of each well. Tabs are provided on the ends of the filter strip for holding the same and supporting the strip in a rectangular holder having alphanumeric designations for identifying each well in a plurality of such filter strips contained within the holder. The filter strip may be used in a vacuum manifold for applying a pressure differential across the filter membrane and directing the filtrate into an aligned aperture of a closed bottom well of an array of wells held within the manifold. Alternatively, the filter strip may be used with a transfer plate for directing the filtrate from each well of the filter strip to an aligned well of a closed bottom array of wells. Another composite assembly includes a pressure manifold for applying an increased pressure above the membranes.