Abstract: The invention relates to a method of detection, a sensor and a test-kit which find application in immunological detection (e.g., immunoassay). The invention provides, inter alia, a method of detection, suitable for use in immunological detection of an entity, which method includes the use of a secondary species (as defined in the specification), the use of a first detectable species, and the use of a second detectable species. The method may include, for example, the use of a primary species, a secondary species, a first detectable species and a second detectable species. The primary species may be, for example, an antibody or a ligand. The secondary species may be, for example, an auxiliary species such as an auxiliary binder or an auxiliary ligand, or a species which has a part which is an auxiliary function. The entity to be detected may be an analyte species as such or may be an entity which carries or includes analytes species.

Abstract: Analytical reagents designated "release tags", for labeling molecular species with a highly detectable signal group which can be released in the form of a volatile compound at a desired point in an analytical procedure. In one embodiment, the release tags have the formula(SgCo).sub.x L(Rx).sub.rwherein each Sg is a signal group bearing one or more electronegative substituents, L is any of a wide variety of groups which when attached to a carbonyl group form a readily cleaved linkage, each COL moiety is a release group which upon scission releases signal group Sg in the form of a volative compound, and each Rx is a reactivity group for attaching the release tag compound to a molecular species to be labeled. In a second embodiment, the release tags have the formulaSgReRxwherein Sg and Rx are defined as above and Re is a release group which is an olefin, .alpha.-hydroxy ketone or vicinal diol. Conjugates of the release tag compounds and assay methods employing them are also disclosed.

Abstract: A release tag reagent suitable for use in the chemical analysis of a substance to be detected comprises signal, release, and reactivity groups. A class of release tag compounds that are cleaved to release as signal groups very stable electrophoric ketones which are sufficiently volatile for determination in the gas phase of an analytical reaction mixture is disclosed.

Abstract: A release tag reagent suitable for use in the chemical analysis of a substance to be detected comprises signal, release, and reactivity groups. A class of release tag compounds that are cleaved to release as signal groups very stable electrophoric ketones which are sufficiently volatile for determination in the gas phase of an analytical reaction mixture is disclosed.

Abstract: D-amino acid oxidase (DAO) in purified, partially purified or crude form is immobilized on a porous bead-shaped support that is a copolymer of vinyl acetate and/or vinyl alcohol and a crosslinking agent. A preferred crosslinking agent is N,N'-divinylethyleneurea. The amount of crosslinking agent is 1 to 60% by weight of the copolymer, and acyloxy groups of vinyl acetate may be present on the support as such or may have been hydrolyzed to hydroxyl groups. The support preferably has a mean particle size of 20 to 800 .mu.m and a mean pore diameter of 2 to 10,000 nm. The D-amino acid oxidase is preferably obtained from Trigonopsis variabilis and purified by ion exchange chromatography. The D-amino acid oxidase may be covalently bonded to a spacer such as epichlorohydrin or its homolog that is bound to the support. Catalase may also be immobilized.

Abstract: A solid support for immobilization of microorganism cells is made of a synthetic polymer such as a polyolefin, in admixture with an organic polymeric plant material such as corn fibers, oat hulls, starch, and cellulose. Preferably, the synthetic polymer is in an amount of about 50-95% wt-% and the plant material is in an amount of about 5-50 wt-%. Preferred polyolefins are polyethylene and polypropylene. The plant material may be a mixture including a plant material that functions as a nutrient to enhance growth of the microorganism on the support. The support may be produced by combining the synthetic polymer and plant material to form a composite, dough-like thermoplastic composition. The composition may be prepared in an extrusion mixer and co-extruded as an extrudate to form a shaped article.

Abstract: A multilayer analysis element for determination of total cholesterol is prepared having a light-transmissive water-impermeable support, at least one hydrophilic polymer layer on said support and a spreading layer on said hydrophilic polymer layer(s), and containing in one or more of the layers:(a) at least one enzyme having cholesterol esterase activity,(b) cholesterol oxidase,(c) peroxidase,(d) a color reagent composition, which in the presence of hydrogen peroxide and the peroxidase, produces a color change(e) at least one bile acid compound selected from the group consisting of bile acids, bile acid derivatives and salts of said acids and derivatives, and(f) an alkyl phenoxy polyethoxy ethanol containing in the alkyl group 1 to 20, preferably 7 to 10 carbon atoms, and a polyoxyethylene chain composed of at least 16, preferably 30 to 60 oxyethylene units.

Abstract: Disclosed are DNA sequences which are useful for the synthesis of carotenoids such as lycopene, .beta.-carotene, zeaxanthin or zeaxanthin-diglucoside, that is, DNA sequences encoding carotenoid biosynthesis enzymes. These DNA sequences are the sequences 1- 6, respectively, shown in the specification.Also disclosed is a process for producing a carotenoid compound which is selected from the group consisting of prephytoene pyrophosphate, phytoene, lycopene, .beta.-carotene, zeaxanthin and zeaxanthin-diglucoside, which comprises transforming a host with at least one of the DNA sequences 1- 6 described above and culturing the transformant.

Abstract: A method for preparing an immobilized enzyme conjugate, whereby the enzyme is treated with a polyfunctional amine reactive material for forming a treated enzyme-containing adduct before being immobilized on a solid support which has been contacted with a solution of a polyamine compound. The method is especially preferred for use with glucoamylase, fungal .alpha.-amylase and .beta.-amylase. Immobilized enzyme conjugates formed by use of this method include treated enzyme-containing adducts. The immobilized enzyme conjugates disclosed herein are more stable and the enzymes immobilized therein are more tightly-held than those otherwise obtained and provided.

Abstract: A method, apparatus and kit for assaying the L- and D-optical isomers and optionally the oxidation product derived from a L- (or D-) optical isomer.

Abstract: A method is provided for producing adipic acid. The method comprises the steps of culturing a cell transformant capable of converting a carbon source to catechol for a period of time sufficient to convert said carbon source to catechol, biocatalytically converting the catechol to cis, cis-muconic acid using catechol 1,2-dioxygenase, and hydrogenating the cis, cis-muconic acid to produce adipic acid.Also provided is a heterologous transformant of the host cell having an endangeous common pathway of aromatic amino acid biosynthesis. The heterologous transformant is characterized by the constitutive expression of structural genes encoding 3-dehydroshikimate dehydratase, protocatechuate decarboxylase, and catechol 1,2-dioxygenase.

Abstract: A method for preparing an immobilized enzyme conjugate, whereby the enzyme is treated with a polyfunctional amine reactive material for forming a treated enzyme-containing adduct before being immobilized on a solid support which has been contacted with a solution of a polyamine compound. The method is especially preferred for use with glucoamylase, fungal .alpha.-amylase and .beta.-amylase. Immobilized enzyme conjugates formed by use of this method include treated enzyme-containing adducts. The immobilized enzyme conjugates disclosed herein are more stable and the enzymes immobilized therein are more tightly-held than those otherwise obtained and provided.

Abstract: Enzymes, cells and/or cellular organelles are bound to an insoluble sintered expanded clay support matrix for catalyzing transformations of agriculture and industrial residues in soil and in other environments. In one embodiment, an enzyme is absorbed by the sintered expanded clay support matrix and a phenolic monomer is polymerized or copolymerized on the support matrix containing the bound enzyme. In another embodiment, an enzyme different from the enzyme absorbed by the support matrix is combined with the phenolic monomer and a copolymer of enzyme and phenolic monomer is formed on the support matrix containing the bound enzyme. The phenolic monomer is preferably catechol, pyrogallic acid and/or resorcinol.

Abstract: A single vessel cyclic synthesis process for preparation of a sialyl.alpha.2.fwdarw.3.beta.galactoside is disclosed. In accordance with this process, a sialyltransferase acceptor is sialylated in an aqueous reaction medium by an .alpha.(2,3)sialyl transferase and CMP-sialic acid to form a sialyl donor substrate and CMP. In the presence of the trans-sialidase of Trypanosoma crusi, that sialyl donor substrate provides a sialyl group for a trans-sialidase acceptor, thereby preparing the sialyl.alpha.2.fwdarw.3.beta.galactoside. The .alpha.(2,3)sialyltransferase acceptor is reformed upon trans-sialidation of the latter acceptor, and the sialyl donor substrate is reformed using the .alpha.(2,3)sialyltransferase and a CMP-sialic acid recycling system that combines CMP with sialic acid that is also present in the vessel. The K.sub.m /V.sub.max value for the .alpha.(2,3)sialyltransferase acceptor is less than one-tenth the value of K.sub.m /V.sub.max of the trans-sialidase acceptor for the .alpha.

Abstract: A process for preparing CMP-activated fluorescence indicator-labelled sialic acids is disclosed. According to the process, a 5-acylamido-9-amino-3,5,9-tridesoxy-.beta.-D-glycero-D-galactonoulosonic acid or 5-aminoacylamido-3,5-didesoxy-.beta.-D-glycero-D-galactonoulosonic acid is reacted with cytidine phosphate in the presence of a CMP-sialic acid synthase which is then reacted with a fluorescing compound to give a CMP-activated fluorescing sialic acid. Also disclosed are novel CMP-activated fluorescing sialic acids.

Abstract: A method of providing and sustaining a difference in pH of a first reaction of an immobilized enzyme and a second reaction in a bulk liquid surrounding the immobilized enzyme is carried out with a bilayer pellet containing coimmobilized enzymes. The pellet can contain an enzyme that produces a desired product immobilized in an inner core and urease immobilized in an outer layer. The bulk liquid contains urea and a substrate for the enzyme in the core, and has an acidic pH. The urease reacts with urea diffusing into the outer layer from the bulk liquid to produce ammonia. The ammonia consumes hydrogen ions diffusing into the inner core from the acidic bulk liquid. This provides the enzyme in the inner core with a pH higher than the acidic pH of the bulk liquid suitable for the enzyme to react with the substrate as it diffuses into the inner core.

Abstract: Pancreatin-containing micropellet cores which can be coated with a gastric juice-resistant film are prepared by extruding a mixture containing pancreatin, polyethylene glycol 4000 and a lower alcohol such as propan-2-ol to produce extrudates which break by themselves into fragments, rounding the fragments with the addition of highly liquid paraffin and drying. Propan-2-ol may be present with the paraffin during rounding. The micropellet cores contain 65-85% pancreatin, and have a bulk density of 0.6 g/ml to 0.85 g/ml, a spherical to ellipsoidal shape with a minor axis in the range of 0.7-1.4 mm and a particle size distribution in which at least 80% of the micropellet cores have a minor axis to major axis ratio in the range from 1:1 to 1:2.

Abstract: A single reaction vessel process for the synthesis of a sialylated galactoside is disclosed. The synthesis utilizes a .beta.-galactosidase to catalyze the reaction of a galactose-containing substrate and an acceptor to form a new galactosyl glycoside that is then sialylated using a cyclic multienzyme synthesis system to form CMP-sialic acid that sialylates the formed galactosyl glycoside in the presence of an .alpha.-sialyltransferase. The value of K.sub.m /V.sub.max for the formed galactosyl glycoside as a substrate for the .alpha.-sialyltransferase is less than one-third the K.sub.m /V.sub.max value for the galactose-containing substrate for that .alpha.-sialyltransferase.

Abstract: A process for the synthesis of a glycopeptide using a solid phase matrix is disclosed. The matrix is compatible with aqueous and organic solvents and is comprised of a silica-based solid support to which is linked a two-part spacer group having a chain length of about 12 to about 40 methylene groups. The first part of the spacer is covalently bonded to the silica-based support and has a length of about 3 to about 10 methylene groups. The second spacer part is covalently bonded to the first part of the spacer and comprises the distal end of the two part spacer. The second part is soluble as a free molecule in each of water, dimethylformamide and dichloromethane and has a terminal amine or hydroxyl group to which the C-terminal residue of the peptide portion of the glycopeptide chain is bonded.

Abstract: Myo-inositol in a specimen is assayed by reacting a specimen containing myo-inositol with:a) myo-inositol dehydrogenase using a thio-NADP group or thio-NAD group and an NADP group or NAD group as coenzymes, and which catalyzes a reversible reaction forming myo-inosose from myo-inositol,b ) A.sub.1 andc) B.sub.1to effect a cycling reaction ##STR1## wherein A.sub.1 is a thio-NADP group, thio-NAD group, NADP group or NAD group, A.sub.2 is a reduced form of A.sub.1, when A.sub.1 is a thio-NADP group or thio-NAD group, B.sub.1 is a reduced NADP group or reduced NAD group and when A.sub.1 is an NADP group or NAD group, B.sub.1 is a reduced thio-NADP group or reduced thio-NAD group, and wherein B.sub.2 is an oxidized form of B.sub.1. The change in the amount of A.sub.2 generated or B.sub.1 consumed by the cycling reaction is measured to perform the assay. A composition for performing the assay comprises the above myo-inositol dehydrogenase, as well as the above components A.sub.1 and B.sub.1.

Abstract: Disclosed are methods for the enzymatic synthesis of alpha-sialylated oligosaccharide glycosides. Specifically, in the disclosed methods, sialyltransferase is activated to transfer an analogue of sialic acid, employed as its CMP-nucleotide derivative, to an oligosaccharide glycoside. The analogue of sialic acid and the oligosaccharide employed in this method are selected to be compatible with the sialyltransferase employed.

Abstract: A method for tanning skin is provided in which liposomes containing a DNA repair enzyme are administered to skin in combination with exposure of the skin to UV radiation. The result is an enhanced level of melanin production, i.e., more tanning than achieved by UV radiation alone. The administration of the DNA repair enzymes in liposomes also reduces the level of DNA damage caused by the UV exposure. Accordingly, both the tanning response is increased and the deleterious effect of UV exposure is decreased. The method can be used by the general population as well as by individuals whose skin is susceptible to UV-induced damage.

Abstract: The present invention discloses a method for the enzymatic synthesis of a peptide. A protected peptide having a C-terminal carboxylate group or a protected, N-acyl amino acid having an alpha carboxylate group is reacted with a protected peptide having an N-terminal ammonium group or a protected amino acid having an alpha ammonium group in the presence of a condensation enzyme under conditions in which the carboxylate group and the ammonium group condense to form a protected, uncharged, peptide product. This peptide product is transported across a water-immiscible hydrophobic phase into an aqueous product phase and prevented from back diffusing across the water-immiscible hydrophobic phase. The peptide product can be converted, chemically or enzymatically, to a charged species that cannot back diffuse across the water-immiscible phase into the aqueous reaction phase.

Abstract: Novel articles are provided comprising at least one polymerized surfactant layer and at least one protein layer specifically bound to the surfactant layer. Depending upon the nature of the preparation of the layers, the layers may be formed as a plurality of substantially parallel layers, filaments, tubes, helices or other complex assembly. The articles may be used for improved determination of protein structure, electronic devices, enzyme reactors and in biosensors. Improved methods are provided for electron microscopic analysis of proteins.

Abstract: The present invention discloses a method for the enzymatic synthesis of a peptide. A protected peptide having a C-terminal carboxylate group or a protected, N-acyl amino acid having an alpha carboxylate group is reacted with a protected peptide having an N-terminal ammonium group or a protected amino acid having an alpha ammonium group in the presence of a condensation enzyme under conditions in which the carboxylate group and the ammonium group condense to form a protected, uncharged, peptide product. This peptide product is transported across a water-immiscible hydrophobic phase into an aqueous product phase. This peptide product is removed from the aqueous product phase to prevent back diffusion across the water-immiscible hydrophobic phase. Reverse osmosis and other separation techniques may be utilized to remove the peptide product.

Abstract: A granular enzyme composition is produced, having reduced tendencies to form dust and leave residue, and exhibiting improved stability and delayed release characteristics. The granular composition comprises a core, an enzyme layer and an outer coating layer. The enzyme layer, and optionally the core and outer coating layer, contain a vinyl polymer. The vinyl polymer is preferably a hydrolyzed polyvinyl alcohol or copolymer thereof. The hydrolyzed polyvinyl alcohol has varying degrees of hydrolysis in the core, enzyme layer and outer coating layer. Also disclosed are methods for making such enzyme-containing granules, the methods having greatly reduced processing time.

Abstract: A method is proposed of obtaining a chemical interaction between at least one reagent trapped in sol-gel glass by doping it with the reagent, and diffusible solutes or components in an adjacent liquid or gas phase. The reagents, the solutes or the components can be any organic or inorganic compounds or materials of biological origin including enzymes. The doped sol-gel glass in various forms may be useful as analytical test, chromatographic medium, sensor, catalyst or biocatalyst, electrode or enzyme electrode, or other detection device.

Abstract: A method is proposed of obtaining a chemical interaction between at least one reagent trapped in sol-gel glass by doping it with the reagent, and diffusible solutes or components in an adjacent liquid or gas phase. The reagents, the solutes or the components can be any organic or inorganic compounds or materials of biological origin including enzymes. The doped sol-gel glass in various forms may be useful as analytical test, chromatographic medium, sensor, catalyst or biocatalyst, electrode or enzyme electrode, or other detection device.

Abstract: A bacteria-containing two component polymer gel is provided for solubilizing particulate or colloidal organic materials in wastewater. The gel contains a minor amount of a polymer component that is difficult to solubilize by bacteria in the gel and a major amount of a polymer component that is easier to solubilize by bacteria in the gel. The gel contains bacteria for solubilizing material in wastewater and for solubilizing the gel, and nutrients for the bacteria. The gel also contains a bacteria inhibitor such as sodium sulfide or sodium azide that can diffuse out of the gel at a gel-water interface to allow bacteria to dissolve the gel at the interface while preventing an interior region of the gel from prematurely dissolving. The gel is placed in a housing through which wastewater flows and contacts the gel.

Abstract: A bilayered immobilized enzyme pellet and a process to manufacture this pellet are provided for use in a process involving the simultaneous isomerization of xylose to xylulose and fermentation of xylulose to ethanol. The bilayered pellet is able to maintain the environment where the isomerization reaction occurs within its optimum pH of 7.0 to 8.0 while the fermentation reaction occurs within its optimum pH range of 4.0 to 5.0. This process allows both xylose and glucose sugars to be effectively used as a feedstock for ethanol production by isomerizing the xylose to xylulose and then making the xylulose immediately available for the fermentation process. Because the xylose has been converted to its ketose isomer, xylulose, yeasts which can ferment glucose and xylulose can be used in this process.

Abstract: The present invention provides a method for the enzymatic synthesis of peptides accomplished by shifting the chemical equilibrium that exists in a reaction mixture between charged or ionized reacting amino acids and uncharged or non-ionized peptide product in the presence of a proteolytic enzyme such as thermolysin. The equilibrium is shifted by diffusion of the uncharged peptide product across an ion-rejection membrane which removes the uncharged peptide from the reaction mixture and preferably the diffused uncharged peptide is quickly converted to a charged species that cannot back-diffuse into the reaction mixture so that the uncharged peptide is effectively "pulled" across the membrane.

Abstract: An analytical method and test composition for determining whether an analyte is present in a test sample at a predetermined concentration level by measuring or observing a preselected level of indicator response, e.g., color generation. A subtractive reaction is carried out on the test sample prior to the indicator reaction in order to stoichiometrically and specifically consume a predetermined amount of analyte. The resulting indicator reaction generates the preselected level of indicator response only if the analyte is present at the predetermined concentration level or greater. The subtractive reaction is enzymatically specific for the analyte in the reaction mixture and the amount of analyte consumed can be closely controlled by the amount of a regulating coreactant present at initiation. The method enables the determination of analyte without the need for standards or comparators, e.g., color charts, and therefore is self-indicating.

Abstract: Alcohol oxidase is immobilized by bonding an aminosilane coupling agent to a carrier, bonding a multifunctional aldehyde such as glutaraldehyde to an amino group of the aminosilane, washing the carrier to remove free multifunctional aldehyde and bonding alcohol oxidase to the multifunctional aldehyde bonded to the aminosilane. Washing to remove free multifunctional aldehyde enables immobilizing a one molecule thickness of alcohol oxidase on the carrier since free multifunctional aldehyde is not present to cross-link alcohol oxidase molecules together. A thin layer of alcohol oxidase is advantageous when assaying for alcohol since a thin layer does not retain hydrogen peroxide that can deactivate alcohol oxidase. The carrier preferably contains hydroxyl groups and is porous, and can be a silicate-containing carrier such as diatomaceous earth or fire brick.

Abstract: An integral multilayer element for chemical analysis utilizing an oxidase enzyme reaction system is prepared having in the following order:(a) a porous spreading layer;(b) an oxygen-permeable, protein-impermeable light-blocking layer;(c) an oxidase-containing layer;(d) an indicator layer containing peroxidase and a hydrogen peroxide indicator showing detectable change in the presence of peroxidase and hydrogen peroxide; and(e) a water-impermeable, light-transmissive support. The oxidase in the oxidase-containing layer is preferably glucose oxidase to provide a multilayer element for glucose determination. This multilayer element shortens the analytical time, widens the measurable concentration range of the analyte and improves accuracy.

Abstract: A biosensor for the determination of glucose and fructose concentrations is provided. The biosensor is produced by a method which comprises treating Zymomonas mobilis whole cells with an organic solvent such as xylene and n-butanol, immobilizing the treated whole cells onto a support selected from the group consisting of gelatin, collagen, agarose, cellophane and polyacrylamide to give an immobilized whole cell enzyme membrane and adhering the membrane to the surface of a pH electrode to give the biosensor. The resulting biosensor is capable of determning glucose and fructose in high concentrations such as 5 g/L and 50 g/L, respectively. Invertase can be immobilized with the whole cells to provide a biosenser for the determination of sucrose.

Abstract: Oxygen-independent methods, systems and devices for the enzymatic colorimetric assay and detection of biochemical analytes. Two systems are described, both of which produce less than one equivalent of dye per equivalent of substrate, maintaining dye concentrations in the range where Beer's law predicts a linear color-concentration relationship. One system produces an analog color signal from an analog analyte input, the other system produces a digital color signal from an analog analyte input.

Abstract: An enzyme electrode for measuring malto-oligosaccharides having a co-immobilized enzyme membrane containing glucoamylase and a glucose oxidizing enzyme such as glucose oxidase or pyranose oxidase.The glucoamylase and glucose oxidizing enzyme are immobilized at a ratio of ##EQU1## where Va is the maximum reaction rate of glucoamylase as expressed in the glucose formation rate from maltose, and Vo is the maximum reaction rate of glucose oxidizing enzyme as expressed in the hydrogen peroxide formation rate from glucose.In such enzyme electrode, malto-oligosaccharides are detected at the response value proportional to their degree of polymerization. Therefore, the malto-oligosaccharides can be measured at the glucose converted concentration.

Abstract: Superoxide dismutase is chemically modified with poly(alkylene oxide), the modified superoxide dismutase having a molecular structure in which both ends of a poly(alkylene oxide) molecule are attached to superoxide dismutase. The modified superoxide dismutase can be used to remove toxic substances derived from oxygen, from the blood circulation in a living body, and has a longer half life in the blood circulation as compared to superoxide dismutase which has not been modified.

Abstract: Specific sialyl transferases (ST) are important enzymes in the manufacture of carbohydrate moieties useful for pharmacological purposes and for diagnostic and clinical procedures. The invention offers simplified methods to isolate highly specific forms of these ST enzymes by taking advantage of the affinity of the ST for its acceptor substrate in the presence of the sialyl-CMP analogs, such as CDP. Specifically exemplified are isolation of the alpha 2,3-ST, specific for Le.sup.c or LacNAc, and alpha 2,6-ST specific for LacNAc.

Abstract: A composition for removing metal ions from aqueous solution is prepared by immobilizing metal ion-binding microorganisms such as algae, washing the immobilized microorganisms, drying the washed immobilized microorganisms and heating the dried immobilized microorganisms to a temperature of about 300.degree. to about 500.degree. C. for a time sufficient to provide a stable composition that is non-swelling in aqueous solution. The composition preferentially adsorbs precious metal ions from an aqueous solution containing concentrations of base metal ions and/or other dissolved materials several orders of magnitude greater than the concentration of the precious metal ions. The composition can also be used to extract precious metal ions from geothermal fluids.

Abstract: The present invention provides a method for the enzymatic synthesis of peptides accomplished by shifting the chemical equilibrium that exists in a reaction mixture between charged or ionized reacting amino acids and uncharged or non-ionized peptide product in the presence of a proteolytic enzyme such as thermolysin. The equilibrium is shifted by diffusion of the uncharged peptide product across an ion-rejection membrane which removes the uncharged peptide from the reaction mixture and preferably the diffused uncharged peptide is quickly converted to a charged species that cannot back-diffuse into the reaction mixture so that the uncharged peptide is effectively "pulled" across the membrane.

Abstract: A system for quantitative colorimetric analysis of biological fluids or organic compounds, including NAD(P)H, or a substrate of an enzyme which reacts with the formation or consumption of NAD(P)H. Concentrations of organic substrates for example alcohol, cholesterol, uric acid, in a biological fluid such as saliva, blood or urine may be determined. The system gives a digital reading of the organic material the concentration which is sought to be determined; the concentration of NAD(P)H is determined by a color change or color "signal" when the NAD(P)H is above a threshold concentration and by the absence of a color signal when the concentration of NAD(P)H is below the threshold concentration. The system includes a chromogen, an electron-accepting reactant which, until exhausted, prevents a visible color change due to accumulation of reduced chromogen, and a catalyst.

Abstract: An assay system useful for the determination of NAD(P)H, NAD(P), or a substrate of an enzyme which reacts with the formation or comsumption of NAD(P)H. Concentrations of organic substrates for example alcohol, cholesterol, uric acid, in a biological fluid such as saliva, blood or urine may be determined. The system includes a diaphorase which catalyzes a NAD(P)H-dependent reduction of a chromogen to cause a visible color change; this color change is indicative of the concentration sought to be determined. The system includes a chromogen which is a first substrate for the diaphorase which causes a color change when reduced by NAD(P)H, and a second substrate which is a competing substrate for the diaphorase; the competing substrate is irreversibly reduced by the diaphorase. The system is capable of measuring colorimetrically without dilution concentrations of organic compounds in biological fluids which previously could not be measured in such concentration.

Abstract: A method and apparatus are disclosed which are directed to the use of dielectrophoresis to levitate, in three-dimensions, a neutral particle such as a biological cell. There is disclosed the use of dielectrophoresis wherein a unique combination of a particular electrode configuration and the use of an active feedback control system is utilized to obtain more precise dielectric properties of the particle.

Abstract: The present invention provides a stabilized sarcosine oxidase preparation which contains creatineamidinohydrolase covalently bound to a water-soluble polysaccharide.

Abstract: Method for the bioluminescent dosing of enzymes, substrates or enzymatic inhibitors, characterized in that there is used a transparent support made of synthetic plastic material previously treated with a charged hydrophilic substance for the Fixation by adsorption of an enzymatic system containing at least a luciferase. The invention extends to a support of the polystyrene type treated by a charged hydrophilic substance on which an enzymatic system containing at least a luciferase is fixed by adsorption.

Abstract: A process is disclosed for the production of substantially pure fructose from sucrose-containing substrates. The process comprises converting the sucrose to levan and glucose, purifying the levan by membrane technology, hydrolyzing the levan to form fructose monomers, and recovering the fructose.

Abstract: A process for preserving the phosphorylating activity of brewer's yeast by means of the intracellular immobilization of the glycolytic enzymes by glutaraldehyde. The process provides the following steps:permeabilization of the cell wall by the combined effect of temperature and the osmotic shock caused by the addition of a concentrated solution of dextrose and phosphates;immobilization of the glycolytic enzymes by cross-linking with intracellular proteins;protection of the SH groups against possible oxidation by the addition of deproteinized yeast extract.

Abstract: A method for enzyme immunoassay includes contacting under binding conditions a liquid suspected of containing an analyte, an antianalyte affixed to a solid support and a tracer having an enzyme conjugated thereto. A bound fraction is separated from the liquid and incubated in a second liquid with a masked ligand. The masked ligand is converted by the enzyme on the bound fraction to give free lignad which binds to an antiligand. A signal system, such as a signal enzyme and substrate therefor, or a label-loaded vesicle and vesicle lysing agent, is added to generate a signal used to detect or measure the analyte in the liquid. The invention includes a kit of materials useful in performing the assay of the invention.

Abstract: A method for producing oligosaccharides which are represented by the general formula Gal-(Gal)n-Glc (where Gal is a galactose residue, Glc is a glucose residue, and n is an integer from 1 to 4) which is characterized in that lactose or a lactose-containing substance is treated with at least two kinds of .beta.-galactosidases which are produced by different microorganisms. The present invention provides a method of producing oligosaccharides to obtain sweet saccharide mixture which provide sweetness and add oligosaccharides to food and drinks, with a lower increase in calories than that of conventional additives.