Abstract: In an apparatus which applies periodic pulsation to a solution flowing through a conduit while undergoing perfusion by a pump, a first valve is disposed in the conduit downstream of the pump, a bypass line is provided to the conduit downstream of the first valve, and a second valve is disposed in the bypass line for withdrawing some of a first pulsed flow formed in the conduit by opening and closing the first valve, through the bypass line as a second pulsed flow. A valve driving circuit periodically opens and closes the first valve and second valve at predetermined time schedules so that the second pulsed flow is superimposed upon the first pulsed flow to form a waveform in the conduit. Any desired pulsatile waveform can be obtained by adjusting the pulse width, the crest values, the delay time, etc., of the two pulsed flows.

Abstract: An apparatus for carrying out chemical reaction sequences includes a stack of reaction plates arranged one above another and displaceable according to choice step by step in relation to one another, which are provided with passages arranged at the stepping interval, one of which passes in each case is formed as reaction chamber. A plate displacement device serves for the displacement of the respective plate, according to choice, in relation to the remaining plate stack. A pressure application part of a clamping device is provided with a faculty for movement of the plates in relation to one another between a pressure application position with sealing clamping together of the plates and a release position.

Abstract: A method for isolating kerogen from a mineral sample in a pressurized reaction cell, which permits reaction at pressures greater than two atmospheres and provides for the removal of all liquids from the cell without significant loss of sample solids, employing multiple steps of addition and removal of concentrated hydrochloric acid, concentrated hydrofluoric acid, concentrated ammonium hydroxide, and deionized water.

Abstract: An analysis system for analyzing a biological fluid or the like for a constituent of the interest includes metal body structure with sample flow path channel structure that serially interconnects heater chamber structure, recess structure for receiving a reaction chamber cartridge and an analysis region to which a measuring system is coupled. The reaction chamber cartridge preferably includes reaction chamber structure with an immobilized enzyme in the reaction chamber that is capable of converting the constituent of interest to a constituent detectable by the measuring system. Cooperating with the metal body structure is a transparent face plate structure which permits visual observation of the sample flow path in the metal body structure.

Abstract: A method and device are disclosed for culturing of adherent cell monolayer cultures on an electrode surface and subjecting the cells to an electrical field. The device may generally comprises cell culture dish, for example a petri-type dish, having a bottom, with an electrically conductive, optically transparent coating amenable to cell adhesion on the upper surface of the bottom. A metal electrode may contact the underside of the coating and is connected to a source of electrical power. The method involves use of the device for culturing the cells under the intermittent or continuous influence of an electric field, or during the establishment of an electrical field or potential. Further, a method and device are disclosed for the sensing of cell poration, and the use of this information to automate the process of electroporation. Further yet, a device and method are disclosed for use in assisting in the time-correlated mapping of the sequence of serial and parallel gene replication.

Abstract: A constant-temperature air type automatic analysis apparatus includes: a reaction table for rotating a row of reaction containers; a batch injecting device for supplying a sample and a reagent into the reaction containers; a photometric device for measuring a reaction within the reaction containers; a constant-temperature air device for keeping the reaction containers warm, the constant-temperature air device having an annular constant-temperature air chamber which is formed in such a manner as to surround the row of reaction containers; a heat block disposed within the annular constant-temperature air chamber; and a preliminary temperature raising device for heating the reaction containers. The preliminary temperature raising device has an air circulation passage, a blowing device for blowing a constant-temperature air against the reaction containers in a region between a injection position of the batch injecting device and a measuring position of the photometric device.

Abstract: There are described assay devices having a control surface on which controls are deposited to produce a representational symbol that preferably indicates a satisfactory test procedure, or a failure in the test procedure. In one aspect of the invention, the symbol comprises exclusively the positive control areas and the negative control area, so that the negative control area will convert the "satisfactory" symbolism into "unsatisfactory" symbolism. In another aspect, the symbols that are formed are "OK" and "OK", respectively.

Abstract: A device for carrying out an analytical determination which comprises an assay cassette and a transport body which is adapted for location in the assay cassette, the assay cassette having a plurality of discrete reagent chambers which are separated from one another by a separation arrangement which, in use, is ruptured or opened by the transport body. An assay cassette is also described which includes a signal detection chamber that is separated from the final reagent chamber by a separation arrangement which, in use, is ruptured or opened by the transport body.

Abstract: A method of extracting cellular components, e.g., nucleic acids, particularly DNA, from biological, expecially solid tissue, samples, particularly from plants is provided, whereby all of the steps can be performed in one vessel, and the entire process can be automated. A vessel suitable for this process is provided, as well as a system for the automated performance of the process steps.

Abstract: In order to improve the response behavior of an optical sensor for determining at least one parameter in a liquid or gaseous sample, the sensor including a substrate which is provided with carrier particles and a fluorescent indicator immobilized thereon, the substrate is configured as a polymer film transparent to both excitation and emission radiation, and the individual carrier particles carrying the fluorescent indicator in immobilized form are bonded with only part of their surface to a thin layer of a thermoplastic material adhering to the polymer film and assume thermosetting properties after the carrier particles have been pressed in, whereas the other part of the surface of the carrier particles extend into an optically transparent hydrogel layer which covers the thermoplastic layer and in which the carrier particles are anchored mechanically. Such sensors may easily be attached to the end of an optical waveguide and may be made in any size by a simple punching operation.

Abstract: This invention encompasses porous microchambers which contain cells and permit liquid to flow in and out of the chamber while retaining cells within the chamber. These porous microchambers serve as disposable devices for placing cells in a microflowchamber so that properties of the cells within the porous microchamber can be measured.

Abstract: There is disclosed an apparatus, a device, and a method using the inventive device and apparatus for the sequential enrichment of a particular microorganism to a threshold level to allow for its detection. The use of the apparatus for sequential microbial enrichment shortens the time period normally spent to enrich samples to permit the growth of enough microorganisms to detect the particular microorganism(s) of interest. The invention eliminates the need for multiple manual transfers of potentially biohazardous materials.

Abstract: The invention is a method for the isolation of palynological materials from a rock sample in a pressurized reaction cell, which permits reaction at pressures greater than two atmospheres and provides for the removal of all liquids from the cell without significant loss of sample solids, the method employing multiple steps of addition and removal of concentrated and dilute hydrochloric acid, concentrated hydrofluoric acid, concentrated ammonium hydroxide, concentrated nitric acid and deionized water, followed by centrifugation and zinc bromide separation steps.

Abstract: A kit of highly uniform size microbead standards for flow cytometer alignment, compensation, and/or calibration, comprising a blank microbead population and/or an auto-fluorescent microbead population, together with two or more series of calibrated microbead populations labeled with fluorescent dye(s) which (i) prior to fluorescent dye(s) labeling, match the fluorescence spectra and fluorescence intensity of the blank and/or autofluorescent microbead population, and (ii) after fluorescent dye(s) labeling, match the fluorescence spectra and fluorescence intensity of fluorescently labeled samples to be measured on the flow cytometer. Also disclosed is a corresponding method to align, compensate, and/or calibrate a flow cytometer so as to make measurements on samples comparable and independent of the specific instrument and instrument settings.

Abstract: A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

Abstract: Waveguides suitable for use in optical assay techniques are described, as well as methods of assay employing such waveguides. The waveguide comprises an input grating structure to couple excitation radiation into the waveguide, a reflecting grating structure to reflect the excitation radiation propagating within the waveguide, and a transduction region located between the two grating structures, whereby during use the excitation radiation traverses the transduction region at least twice.

Abstract: A flow cytometer reference standard containing a highly uniform microbead population, wherein each microbead has the same multiple fluorescent labels as the other microbeads and as the samples to be measured. Target conditions are set for the sample after alignment of the flow cytometer. The microbead reference standard is used to determine peak channels (target channels) for each parameter. The target conditions may be reestablished for later uses of the flow cytometer with the same type of samples by using the microbead reference standard to adjust the flow cytometer so that the microbead peak channels fall in the originally determined target channels.

Abstract: Highly uniform microbeads containing a single fluorescence dye or a mixture of fluorescence dyes, which can be excited over a wide range of the spectrum extending from the ultraviolet to the infrared, and which can be used to align a flow cytometer or fluorescence microscope.

Abstract: A novel class of nonpermeating cryoprotectants which, when mixed with certain known penetrating cryoprotectants, provide a useful medium for protection of living cells during a cryopreservation process. Algae-derived polysaccharides such as agarose and alginate are useful as nonpermeating cryoprotectants as they form a gel matrix when cooled, protect against ice crystal formation, and yield improved viability of cells when thawed.

Abstract: Device for replica plating of living cells. The device includes a rigid base having a side wall connecting a first upper surface and first lower surface, and a water absorbing fabric free from dye and preservatives having a second upper surface and a second lower surface. The second lower surface is fixedly bonded to the first upper surface in a manner which prevents any horizontal or vertical movement of the fabric which would cause inaccurate transfer of the cells by the device. The base further includes an adhesive tab positioned on the first lower surface. The tab is configured and arranged to fixedly secure the base to a flat surface and thereby fixedly secure the fabric in a positioned raised above the flat surface and accessible for replica plating of the cells. The device may also contain integral marking element and bumper guards.