Abstract: This invention is a debubbler, degasser or gasser device used to remove gas bubbles and/or dissolved gasses from a liquid stream or to add gasses to a liquid stream. The device consists of a first block, a hydrophobic membrane, and a second block. The first block has a channel for carrying liquids which is grooved into its lower surface. The end of the channel is connected to an inlet and outlet. The second block has venting holes. When the hydrophobic membrane is pressed between the first and second block liquid can flow through the channel and bubbles or dissolved gasses in the liquid stream pass through the hydrophobic membrane. Alternatively, or in combination with degassing or debubbling, the device may be employed to introduce into the liquid stream gasses provided on the opposing side of the hydrophobic membrane.

Abstract: The present invention encompasses a method for removing proteins from a solution containing polynucleotides and proteins comprising filtering the solution through a nitrocellulose membrane at neutral or basic pH.

Abstract: Picogram amounts of DNA can be detected in a sample by the use of high affinity single-stranded DNA binding proteins. The assay is applicable not only to pure DNA samples but also to samples containing significant amounts of protein.

Abstract: A multibeam photometric measuring device includes a single light source along with a filter assembly for passing only a desired band of wavelengths and an optical system for suitably focusing light from the light source. Light is transmitted individually to each of a plurality of sites disposed on a multi-well sample plate. Enhancement of color distribution is provided by automatic agitation of the reacting agents within the sample wells before a reading is taken at each of the sampling intervals of a kinetic measurement sequence.

Abstract: Devices and methods are provided for determining the presence and amount of an analyte by measuring a redox potential-modulated photoinducing signal from a photoresponsive element. Further devices and methods are provided for determining the presence and amount of an analyte by measuring a redox potential, pH or ion modulated photoinduced signal from a photoresponsive element, where one signal is a constant system and the other signal(s) is a variable system. The constant system signal is used to standardize the variable system signal. Various protocols may be employed where an analyte may be directly or indirectly coupled to a redox couple, a pH or ion system for detection. The latter devices employ a photoresponsive element having a medium contacting surface, which is partially covered with an electronically conducting layer and partially covered with a protective insulative layer.

Abstract: Picogram amounts of DNA can be detected in a sample by the use of high-affinity, single-stranded DNA binding proteins. The assay is applicable not only to pure DNA samples but also to samples containing significant amounts of protein.

Abstract: Novel methods and devices are provided for detecting analytes, where the sample is placed upstream from a reagent which is a component of a signal-producing system. The detection zone is provided upstream from the sample, where the amount of reagent which becomes bound at two sites is determined and the two values used for an accurate determination of an analyte.

Abstract: Enzyme or substrate determinations can be achieved by employing an organic second substrate, which produces a product which may be coupled with a metal inorganic redox couple capable of interacting with and affecting the potential of a metal electrode on a semiconductor surface. Particularly, hydrogen peroxide or indoxyl phosphate are coupled with iron- or ruthenium-containing ionic redox couples for determination with a noble metal electrode.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: A method of analyzing selected regions of semiconductor systems to determine the uniformity of distribution of trapped charges or electric dipoles at the surface of the semiconductor or in a dielectric or insulating material associated therewith, the method including the steps of applying an adjustable bias potential to the semiconductor system to produce an electric field within the system; directing a beam of electromagnetic radiation onto a selected region of the semiconductor system in which the electric field exists to induce a photocurrent output from the system, the beam including photons of energy greater than the band gap energy of the semiconductor; adjusting the bias potential to vary the direction and/or the magnitude of the electric field; measuring the photocurrent output induced by the beam as a function of the bias potential; and determining the uniformity of distribution of trapped charges or electric dipoles in the selected region of the semiconductor system from the measured photocurrent ou

Abstract: A microtiter plate prepared from a hydrophobic plastic is rendered more hydrophilic by treatment of the surfaces of the wells of the microplate prior to use. The resulting plates are particularly useful in vertical beam photometry.

Abstract: An apparatus for determining a characteristic of a signal modulating component related to an analyte of interest at an assay site by measuring light modulated by the component. A light source uniformly illuminates the assay site and a reference site. The light is directed from the sites onto a group of memory cells on the surface of a random access memory. The memory cells will decay from a logical 1 to a logical 0 due to the light over a period of time which is a function of the intensity of the light and the reference voltage of the memory cells marking the difference between a 1 and a 0. The digital state of each of the memory cells in the group is measured a predetermined exposure time. The measured states of a group of memory cells corresponding to the assay site are compared to the memory cell states for a reference group. The measured states are then analyzed to determine a characteristic of the analyte.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: Photoresponsive devices, including a photoresponsive electrode, are provided and methods for their use to measure changes in environment at a site at or about the surface of the photoresponsive device. By employing a source of light for irradiating a site on the surface and means for biasing the photoresponsive electrode in relation to a counterelectrode, a variation in electrical signal can be related to a change in a medium in photoresponsive modulation relationship to the photoresponsive electrode surface.

Abstract: Electroanalytical elements are provided involving a polarity-sensitive layer; a first lipid layer non-diffusively bound to said polarity-sensitive layer; and, a second amphiphilic layer, with hydrophilic heads distal from said first lipid layer and defining a polar layer which interacts with said polarity-sensitive layer. The device is used in polar media to detect variations in the electrostatic interaction between the polar layer and the polarity-sensitive layer.