Abstract: The concentration of thyroxine binding globulin (TBG) in a fluid sample can be determined via radioassay technique with an immunochemical composite comprising anti-TBG antibodies immobilized on a water-insoluble carrier. The composite is incubated with the sample in a quantity sufficient to assure complexation of substantially all TBG in the sample to the antibodies of the composite. The quantity of TBG complexed is determined with radiolabeled thyroxine (T.sub.4) which complexes with at least a portion of the complexed TBG. By separating the labeled composite from the remaining labeled T.sub.4, and counting the bound (or unbound) T.sub.4, the concentration of TBG can be determined from a standard curve.

Abstract: A glass article having relatively high degrees of surface smoothness, durability, and light transmissivity can be made by forming a glass comprising, in mole percent on an oxide basis, 70-80% SiO.sub.2, 8-18% Na.sub.2 O and/or K.sub.2 O, and 5 to 10% of ZnO and/or PbO; hydrating the glass under acidic conditions to include a water content of up to 12% by weight while reducing the alkali content; reacting the hydrated glass with a HF-containing solution to remove up to 30 weight % of the glass; dehydrating the glass, if necessary, to reduce the total water content to a range of 3 to 7 weight percent; and pressure molding the glass under conditions sufficient to impart an optical quality surface smoothness of a die to the glass surface.

Abstract: The half-life of enzymes which have been immobilized by chemical coupling via silane coupling agents to inorganic carriers is increased significantly by using a carrier which has been treated to increase its water-durability. Treatment of the carrier comprises the steps of first coating the carrier with a solution containing a metal, the oxide of which is more water-durable than the carrier, and then firing the coated carrier to form a continuous metal oxide layer on the carrier surface. The treated carriers are then silanized for chemical coupling wih enzymes. Methods for preparing and using enzyme composites having the improved carrier are disclosed.

Abstract: Method of detecting and/or quantitating anti-virus antibodies comprising the steps of reacting serum containing an unknown amount of a given antibody, a known amount of the antibody (radioactively labelled), and a composite consisting of the antibodies coupled chemically through an intermediate silane coupling agent to a porous glass body, the composite having complexed thereto quantities of the virus; separating the composite from the reaction solution after a suitable reaction period; determining the radioactivity count of the separated composite or the remaining solution; and, relating the count to a standard curve.

Abstract: Gel-like compositions useful for separating and partitioning whole blood into serum and clot portions. The composition comprises a polybutene liquid polymer having an inert high surface area inorganic filler dispersed therein, the filler being present in an amount sufficient to impart to the composition a specific gravity ranging from about 1.030 to about 1.090 and a viscosity ranging from about 200,000 to about 850,000 centistokes. When centrifuged in the presence of whole blood, the composition forms a chemical and physical barrier between the serum and clot portions.

Abstract: Useful products such as molecular hydrogen can be continuously produced by reacting a solution of a substrate in the presence of light with a photometabolically active microbe which has been stabilized on a support. In one embodiment, Rhodospirillium rubrum bacterial cells are mixed with agar gel and the mixture is spread over a plate which is placed in a transparent flow-through reactor. Then, an aqueous malate solution is passed through the reactor under essentially anaerobic conditions in the presence of light to yield molecular hydrogen. In another embodiment, Blue-Green algae are similarly stabilized for continuous biophotolysis of water by oxidizing the water and reducing NADP to NADPH. Other photosystems for producing useful products are disclosed.

Abstract: Highly porous MgO-Al.sub.2 O.sub.3 particulate support materials useful for the immobilization of glucose isomerase can be regenerated for reuse by circulating a sodium hypochlorite solution through the particles thereby permitting in situ enzyme carrier regeneration.

Abstract: An efficient immobilized glucose isomerase composite can be prepared by adsorbing the enzyme within the pores of a porous inorganic support having an average pore size between about 100 A and 1000 A and consisting of about 0.84% to 12.0% MgO and 99.16% to 88.0% Al.sub.2 O.sub.3, by weight.

Abstract: Proteins such as enzymes or antibodies can be immobilized in a biologically active state on various inorganic supports via an intermediate residue of o-dianisidine.

Abstract: An efficient immobilized glucose isomerase composite can be prepared by adsorbing the enzyme within the pores of a porous inorganic support having an average pore size between about 100 A and 1000 A and consisting of about 0.84% to 12.0% MgO and 99.16% to 88.0% Al.sub.2 O.sub.3, by weight.

Abstract: The viscosity of a silica-silicone oil gel-like composition useful as a partitioning substance in blood collection tubes can be controlled by first preparing a mixture of a silicone oil and silica particles to form a mixture having a viscosity greater than about 200,000 centistokes, reacting the mixture in an evacuated environment at a temperature ranging from about 175.degree. to 550.degree.C. for a period of time sufficient to reduce the viscosity below about 120,000 centistokes, and then adding a network former to the reaction mixture in a quantity sufficient to increase the viscosity to a range of about 200,000 to 600,000 centistokes, preferably to a range of about 350,000 to 450,000 centistokes.

Abstract: Method of determining the concentration of a substance in a solution which comprises the steps of incubating the solution with a known amount of radioactively labelled substance and a suspendable composite consisting of anti-substance antibody coupled chemically through an intermediate silane coupling agent to an inorganic carrier, the incubation period being for a time sufficient to form immunochemical complexes, separating the complexes from the solution, determining the radioactivity of either the separated complexes or the remaining solution, and relating that determination to a standard curve. Specific assays for digoxin, insulin, and estriol are disclosed.

Abstract: Highly porous MgO-Al.sub.2 O.sub.3 support materials useful for the immobilization of glucose isomerase can be regenerated for reuse by pyrolysis under conditions sufficient to remove substantially all carbonaceous matter, followed by treatment with a neutralized citrate solution.

Abstract: A relatively constant concentration of the electrolytic salt bridge solution within a pH reference electrode is maintained by including crystals of the electrolyte salt in a concentrated but not saturated solution. In a preferred electrode, the electrolytic salt bridge is a concentrated KCl solution (e.g. about 4 M/l) within which KCl crystals are held in place by an inert foraminous material disposed intermediate an internal reference electrode and a passageway in the electrode housing through which is established electrochemical contact between the salt bridge and a fluid, the pH of which is to be measured.

Abstract: Nicotinamide-adenine-dinucleotide (NAD) can be coupled chemically to an essentially water-insoluble carrier material selected from the group consisting of glass particles having a diazotizable silane coupling agent attached thereto, p-aminobenzylcellulose, polyaminopolystyrene, and the half amide of benzidine-carboxymethylcellulose by diazotizing the carrier materials and reacting the diazotized materials with a solution of NAD. Methods of chemically coupling the NAD to such carriers are disclosed and the redox activity of NAD coupled to porous glass beads through an intermediate silane coupling agent is demonstrated.

Abstract: Bacterial cells (Streptomyces sp.) having glucose isomerase activity can be aggregated with an aqueous solution of tetrazotized benzidine and used as an immobilized enzyme system for the isomerization of dextrose (glucose) to levulose (fructose).

Abstract: Clinically significant concentrations of digoxin can be determined by reacting an unknown amount of digoxin, a known amount of labelled digoxin, and a composite consisting of anti-digoxin antibodies coupled through an intermediate silane to magnetically responsive particles; magnetically separating the immunochemical complexes formed thereby, counting the radioactivity of either the separated products or remaining solution, and relating the count to a standard curve.

Abstract: Enzymes can be coupled chemically to various water-insoluble inorganic carriers by reacting the carriers with 4,4'-bi(methoxybenzenediazonium chloride) to form a surface of diazo groups which are subsequently reacted with an enzyme solution to immobilize the enzymes. In preferred embodiments, the inorganic carriers are highly porous, have an average pore size of less than about 1000 A, and consist of 4-200 mesh porous particles of materials selected from the group consisting of glass, silica, alumina, and mixtures of silica and alumina.