Abstract: A process and apparatus for detecting the mobility of fluorescently labeled molecules in response to a force is disclosed. The fluorescently labeled molecules are placed in a fluid medium such as an electrophoretic gel in a capillary tube. An electric field is applied to induce the movement of the molecules. A region of the labeled molecules is photobleached leaving a geometrically defined region which has not been photobleached. The region which has not been photobleached is excited by a reading beam. The reading and the photobleaching beams can be generated by focusing a laser through a diffraction grading. The intensity produced by the interaction of the reading beam in the geometrically defined region of the molecule is detected by a photo detector. In detecting more than one spThis invention was partially made with Government support under the polymers program of the National Science Foundation DMR8617820. The Government has certain rights in the invention.

Abstract: As the conventional simple bio-sensors for measuring the particular component in living bodies, there are those in which a change in dye caused by enzyme reaction is detected optically, but such bio-sensors had a problem that precision is low owing to disturbance of the color of liquid samples. With bio-sensors using an enzyme electrode, the precision was high, but operation of measurement was troublesome. The present invention made it possible to detect the concentration of the particular component electromechanically with rapidity, simplicity and high precision by merely putting a porous substrate containing at least enzyme on the electrode system and impregnating the body with a liquid sample.

Abstract: Amplification of nucleic acids is performed by incubating in a polymerization vessel a reaction mixture which contains in a suitable buffer solution, one or several single-stranded target nucleic acids, suitable primers, deoxyribouncleoside triphosphates and a polymerase. After a sufficient time for polymerication to occur, the reaction mixture is transferred into another vessel for the denaturation of the nucleic acids into single stranded nucleic acids. After denaturation, the reaction mixture is transferred back into the original vessel. The amplification process is regulated to maintain a temperature advantageous for the action of the polymerization enzyme in the polymerization vessel and a temperature advantageous for denaaturation in the denaturation vessel.

Abstract: A device for detecting the presence of a particular motile organism within a sample are disclosed. The sample may be derived from dry milk, raw meat, poultry or a clinical specimen. A preferred method of using the device includes inoculating a selective enrichment medium containing a chemotactic attractant with the sample and contacting the selective enrichment medium with a nonselective motility medium containing a chemotactic attractant in a concentration less than the attractant concentration in the selective enrichment medium. Upon incubation, the motile organism metabolizes the chemotactic attractant, allowing the organism to move into the motility medium where it interacts with antibodies specific for the organism, thereby causing the formation of a persistent immobilization band. The device is particularly useful in detecting Salmonella.This application is a divisional of U.S. Ser. No. 773,201, filed Sep. 9, 1985 and issued as U.S. Pat. NO. 4,920,063 on Apr.

Abstract: The invention relates to a gel body of a delimited physical form preferably containing water and characterized in that it a) contains an encapsulated apathogenic micro-organism having a known and reproducible resistance; b) has a porous structure with the size of the pores defined, said structure preventing the encapsulated micro-organism from diffusing out but allows a nutrient solution adjusted to the micro-organism to diffuse in and metabolites produced to diffuse; c) is thermally stable in various sterilization, pasteurization or cooking processes; d) is mechanically stable when transported through the process equipment for sterilization, pasteurization or cooking; e) is surface sterile; and f) is transparent in order to allow observation of possible growth of the micro-organism when incubated in a nutrient solution.

Abstract: In a device for the aeration of composting reservoirs of biomass, each aeration mouth in the biomass being treated is supplied separately and independently from the others by means of a conduit (4) adapted to this effect. All the conduits (4) have an energy drop substantially equal to 5-20 times, preferably 8-12 times more than the energy drop of the air which traverses the biomass. Each conduit (4) is connected to the collector (5) situated outside the reservoir (1) by a closure tap (7) and is provided with a device (9) for injecting in the conduits a high pressure liquid in order to, in case of need, clear the discharge orifices when they are plugged. The conduits (4) and optionally the collector (5) are separated according to the maturity degree of the biomass, in groups having different air volume and pressure. Furthermore, the free end of each conduit (4) which terminates at the bottom (3) of the reservoir (1) acts as an aeration mouth.

Abstract: A method and device involving use of the reaction product of an aldehyde acidified with sulfuric acid in acetone for sensing moisture. The reaction product is used as a coating for colorimetric detection of humidity, the color of the coating changing as a function of the humidity level. The coating is applied to a thin layer chromatography plate which is received in a badge housing to provide a real-time colorimetric dosimeter for monitoring humidity and indicating its presence.

Abstract: The improvement of specimen quality for microbial analysis is addressed by the present invention which discloses a chemical composition for use in a method and apparatus for transporting a specimen suspected to contain microorganisms of interest to a laboratory for analysis and improved methods of analysis.A device and method for taking, storing, and preserving fluid samples is disclosed comprising a container and a composition designed to maintain the level of microorganisms present in a specimen during transportation of the specimen to a testing facility.The method and apparatus can be utilized on all types of aqueous specimens and specimens which may be extracted in aqueous solution for analysis of microorganisms therein.

Abstract: A diagnostic instrument and method indexes plural, sequentially actuated reaction vessels, stepwise to several processing positions. Several positions effecting wash have wash probes that are gauged together. Sample and/or reagent are not added to a number of vessels leading and trailing sample containing vessels. The processing of the sample is controlled according to different time-templates and the first use of the wash probes occurs in the same cycle for different sets of analytical tests.

Abstract: The invention provides an imaging immunoassay detection apparatus system and method capable of detecting multiple light emitting reactions from small volume samples simultaneously and quantifying the same.

Abstract: A method of determining an analyte in an organic or microaqueous solution involves the use of an enzyme electrode at which an enzyme is retained. The enzyme may be immobilised covalently at the electrode but is preferably retained at a hydrophilic support (4) which may be connected to an electrical conductor. Electrochemical detection of analytes in organic or microaqueous solvents using an enzyme electrode has several advantages over existing methods which employ aqueous solutions of analyte. For example compounds with low water solubilities may be detected, detection of a particular analyte may be made more selective by appropriate choice of solvent, the thermal stability of the enzyme may be enhanced and the enzymes may be readily retained at the electrode by virtue of their insolubility in the organic or microaqueous solvent.

Abstract: A qualitative and quantitative method of determining the fluorescence threshold of an instrument and of determining whether the instrument is sensitive enough to measure the autofluorescence of a sample. The method utilizes non-fluorescent particles such a microbeads which are run on a flow cytometer. The peak channel position of the microbeads is used as the fluorescence threshold.

Abstract: The use of a combination of calibrated microbead populations with one or more calibrated biological cell populations to correct calibration of a flow cytometer for size and fluorescence intensity determinations of biological cell samples. The use of calibrated biological cells permits correction for factors related to the instrument and calibration microbeads so long as the excitation and emission spectra of the calibration microbeads, the calibration cells and the cell samples are all the same, respectively.

Abstract: The present invention is related to a technique for storing concentrated eluant, preparing dilute eluant, and reclaiming water used for dilution. The invention uses stored concentrated eluant which is diluted using a sample loop coupled with a dilute eluant reservoir. Water is used for dilution and is reclaimed using a mixed ion exchange bed. The use of concentrated eluant and reclaimable water significantly reduces storage needs.

Abstract: Aqueous acidic ferrioxalate compositions are disclosed for use as calibrants of pCO2 and of PO2 after photodecomposition. Compositions with high iron(III) to oxalate molar ratios (e.g., 5:1 to 100:1 with 0.3 to 15 millimolar oxalate) produce carbon dioxide on exposure without oxygen consumption. Compositions with low iron(III) to oxalate ratios (e.g., 1:100 to 1:2000) with 0.1 to 5 millimolar iron(III) produce carbon dioxide on exposure with concurrent oxygen consumption. Use of the two types of compositions enables calibration values to be established with varying pCO2 values and with, respectively, high and low pO2 values.

Abstract: The improvement of specimen quality for microbial analysis is addressed by the present invention which discloses a chemical composition for use in a method and apparatus for transporting a specimen suspected to contain microorganisms of interest to a laboratory for analysis and improved methods of analysis.An improved method and apparatus for detecting microbial pathogens in a sample body fluid is disclosed which comprises by mixing the sample body fluid with an antimicrobial factor deactivating agent and improver of microbial quantitative integrity within the sample body fluid after it has been collected and before the microbial pathogens are analyzed. An article useful in the concentration of microbial pathogens from a sample fluid and useful in practicing the method of the subject invention is further disclosed.The method and apparatus can be utilized on all types of aqueous specimens and specimens which may be extracted in aqueous solution for analysis of microorganisms therein.

Abstract: This bioreactor comprises two enclosures (60,62) connected by first and second porous carbon tube (66,68) for the circulation of the nutrient medium (19) and immersed in the culture medium (9), internal mineral, microporous membranes (70) located in each first and second tube for ensuring the passage of the nutrient medium to the culture mdium and whilst serving as a barrier for contaminants, external, mineral, microporous membranes (72) located outside each first and second tube for ensuring the passage of the nutrient medium to the culture medium and while serving as barrier for the cells and the proteins contained in the culture medium, at least one porous mineral tube (86) for the extraction of the substances produced by the cells, which is isolated from the two enclosures and equipped with an external, microporous, mineral membrane impermeable to the cells, but permeable to the macromolecules produced in the culture medium.

Abstract: Electrodes for the measurement of pCO2 and/or pO2 are calibrated with an exposed aliquot of a calibration liquid. A constituent such as a ferrioxalate salt in the calibration liquid is converted to the gas in a reproducible concentration by exposure of the aliquot to light. In some instances, the calibration liquid is equilibrated with air prior to exposure. Some mechanisms of light generation of carbon dioxide also consume oxygen, so as to depress the pO2 value by a reproducible amount. The use of two different calibration liquids enables both one-point and two-point calibration of the Clark oxygen electrode and the Severinghaus pCO2 electrode of a blood gas instrument.

Abstract: An enzyme reactor system is provided based on the entrapment of a coenzyme-requiring enzyme, a coenzyme, and a regeneration enzyme in a hydrogel layer coated on a support, and confined by an ultraporous thin film semipermeable membrane. The diffusion barrier confines the coenzyme-requiring enzyme, coenzyme, and regeneration enzyme but lets substrate and reaction products, exclusive of coenzyme, diffuse freely into and out of the hydrogel layer. In an alternate embodiment, the support is formed of an ultraporous thin film semipermeable membrane on a microporous or macroporous support, through which the reaction products, exclusive of coenzyme, can diffuse freely, but through which neither coenzyme-requiring enzyme, coenzyme, regeneration enzyme, nor substrate can pass. In this embodiment, the product is recovered in high purity, free of substrate, coenzyme-requiring enzyme, coenzyme, and regeneration enzyme.

Abstract: A composition is disclosed of blood serum sample preparation for improved, more accurate and precise, electrooptical method for measuring erythrocyte volumes, individually and as an average.