Abstract: An aqueous wash solution is buffered to a pH of from about 5 to about 9 and contains at least about 1.5 weight percent of a compound comprising a lower alcohol sulfate anion having from 6 to 10 carbon atoms and an alkali metal or ammonium cation, such as sodium decyl sulfate. This wash solution is useful in a method for the determination of an immunological ligand, and is not prone to crystallization at lower temperatures. Particularly, it is useful for washing the immunological complex formed between the ligand and a receptor molecule therefor. Unreacted materials can be readily separated from the complex by the washing, particularly if the separation is carried out using a filtration membrane in a test device. A test kit for ligand determination comprises the wash solution as well as one or more receptors for the ligand, at least one of which is labeled for detection. This kit is particularly useful for measuring human chorionic gonadotropin (hCG) as an early indicator of pregnancy.

Abstract: A buffered composition containing a nonionic or anionic surfactant, and a certain amount of a hydroxamic acid (or salt thereof) or an acyl hydrazine can be used as a wash composition in specific binding assays. Such assays include the use of a peroxidase labeled specific binding reactant to form a detectable peroxidase-labeled specific binding complex. The buffered composition and labeled reactant can be supplied in a diagnostic test kit. The hydroxamic acid or acyl hydrazine can be represented by the structure(I):R--CO--NH--R'wherein R is aryl or 6 to 10 carbon atoms in the aromatic nucleus, alkyl of 1 to 7 carbon atoms, cycloalkyl of 5 to 10 carbon atoms in the ring, or heterocyclyl of 5 to 10 atoms in the ring, at least one of which is an oxygen, nitrogen or sulfur atom, and R' is hydroxy or amino.

Abstract: A multilayer analytical element for measuring salicylate is disclosed. The element has a support. The support is coated with the following layers, top down to the support:a) a spreading layer,b) a dye layer having a pH greater than 6.5 and comprising tyrosinase and a water-insoluble hydrazone coupling agent,c) a barrier layer that prevents passage of molecules having a molecular weight in excess of 5,000, andd) a reagent layer comprising salicylate hydroxylase and nicotinamide adenine dinucleotide (NADH), wherein the spreading layer comprises valproic acid, 8-anilino-1-naphthalenesutfonic acid (ANS) or the magnesium salt of 8-anilino-1-naphthalenesulfonic acid.

Abstract: Reagents have been prepared from water-insoluble polymeric particles to which are covalently attached avidin, biotin or an avidin or biotin derivative. The polymeric particles comprise a polymer on at least the outer surface which is derived from at least one ethylenically unsaturated monomer having a reactive activated 2-substituted ethylsulfonyl, vinylsulfonyl or active halogen atom. Covalent attachment of avidin, biotin or an avidin or biotin derivative is effected either directly or indirectly through these reactive groups. The resulting reagent is useful in analytical elements and various analytical methods including agglutination and sandwich assays. The immobilized avidin, biotin or derivative can be used to complex with the corresponding biotin or avidin molecule which may be conjugated to a compound of biological interest.

Abstract: A dry analytical element has been prepared for the assay of leucine aminopeptidase at a pH of 6.5 to 11. The element zone contains an aromatic substrate for the enzyme. This substrate provides an aromatic reactant which has a primary amino group on the aromatic ring in the ortho or para position to an electron donor group. The aromatic reactant is oxidized with an oxidizing compound (such as an oxidase) and the oxidized compound reacts with a ballasted color-forming coupler to provide a dye.

Abstract: An oligonucleotide is linked to a particle through a protein or carbohydrate to form a water-insoluble nucleic acid probe. The protein or carbohydrate has a pI of about 6 or less, and has been chemically modified with an acylating, alkylating or sulfonylating agent. The particle surface is substantially free of other proteins or carbohydrates. The probe is useful in various diagnostic and purification methods wherein hybridization of the oligonucleotide with a target nucleic acid is possible. In one instance, the probe can be used to capture a DNA strand which has been amplified using polymerase chain reaction techniques.

Abstract: A method is provided for preparing a covalent conjugate of an oligonucleotide and an enzyme, such as peroxidase. This conjugate can be used as a probe in hybridization assays and in polymerase chain reaction procedures. The method generally comprises the steps of: reacting an enzyme having a reactive amino group with a mercapto-substituted organic compound to form a blocked intermediate, removing the blocking group to form an enzyme reagent, and reacting the enzyme reagent with a functionalized oligonucleotide reagent.

Abstract: Diluent and wash compositions are useful in a rapid and sensitive assay for detecting antibodies, and especially retroviral antibodies, in a biological specimen. The diluent composition is buffered to a pH of 6 to 10 and includes a protein or carbohydrate, a surfactant and a negatively-charged organic compound. The wash composition is buffered to a pH of 5 to 10 and includes a surfactant. These compositions can be included in a diagnostic kit. The method of this invention includes mixing the biological specimen with the diluent composition, forming an immunological complex between ligand and antibodies in the specimen and separating complexed materials from uncomplexed materials using a filtration membrane and a washing step. An enzyme labeled anti-antibody is added to form a ligand-antibody-antibody complex followed by its detection using suitable reagents.

Abstract: Specific binding methods are used for diagnostic assays and purification separations whereby the specific binding capture reagent is prepared from copolymers having highly reactive carboxy groups. These groups are extended from the polymer surface with a linking group having from 8 to 50 atoms in the chain and two or more alkylene, arylene, alkylenearylene or arylenealkylene groups. To these reactive groups is attached a biologically active substance such as a protein or oligonucleotide which then participates in the diagnostic assays or purification separation methods.

Abstract: A covalent conjugate of an enzyme, such as peroxidase, glucose oxidase, alkaline phosphatase and beta-galactosidase, and an oligonucleotide is herein disclosed. This conjugate can be used as a probe in hybridization assays and in polymerase chain reaction procedures.

Abstract: A buffered composition containing a nonionic or anionic surfactant, and a certain amount of a hydroxamic acid (or salt thereof) or an acyl hydrazine can be used as a wash composition in specific binding assays. Such assays include the use of a peroxidase labeled specific binding reactant to form a detectable peroxidase-labeled specific binding complex. The buffered composition and labeled reactant can be supplied in a diagnostic test kit. The hydroxamic acid or acyl hydrazine can be represented by the structure(I):R--CO--NH--R'wherein R is aryl or 6 to 10 carbon atoms in the aromatic nucleus, alkyl of 1 to 7 carbon atoms, cycloalkyl of 5 to 10 carbon atoms in the ring, or heterocyclyl of 5 to 10 atoms in the ring, at least one of which is an oxygen, nitrogen or sulfur atom, and R' is hydroxy or amino.

Abstract: Heme-containing proteins, such as cytochrome c, are useful in admixture with enzyme-labeled immunoreactants, such as peroxidase-labeled antibodies or fragments thereof. The heme-containing proteins and enzyme-labeled immunoreactants can be supplied in a buffered composition as part of a test kit. The buffered composition comprising the heme-containing protein and peroxidase-labeled immunoreactant excludes 4'-hydroxyacetanilide, which is a phenolic electron transfer agent. The composition can be used in immunoassays for detecting various immunologically reactive species, such as hCG, and chlamydial or gonococcal antigens.

Abstract: A novel 14-crown 4-ether derivative is disclosed for use in a dry analytical element for assaying lithium.

Abstract: Biologically active reagents are prepared from particles of copolymers having highly reactive carboxy or equivalent groups. The reagents are prepared by covalently attaching biologically active substances, for example antibodies, to the particles, directly or indirectly through highly reactive carboxy groups on the particle surface. These reagents are used to advantage in analytical elements, methods for the detection of specific binding ligands (such as immunological species) and immunoassays, and in purification methods as affinity chromatography reagents.

Abstract: A covalent conjugate of an enzyme, such as peroxidase, glucose oxidase, alkaline phosphatase and beta-galactosidase, and an oligonucleotide is herein disclosed. This conjugate can be used as a probe in hybridization assays and in polymerase chain reaction procedures.

Abstract: Diluent and wash compositions are useful in a rapid and sensitive assay for detecting antibodies, and especially retroviral antibodies, in a biological specimen. The diluent composition is buffered to a pH of 6 to 10 and includes a protein or carbohydrate, a surfactant and a negatively-charged organic compound. The wash composition is buffered to a pH of 5 to 10 and includes a surfactant. These compositions can be included in a diagnostic kit. The method of this invention includes mixing the biological specimen with the diluent composition, forming an immunological complex between ligand and antibodies in the specimen and separating complexed materials from uncomplexed materials using a filtration membrane and a washing step. An enzyme labeled anti-antibody is added to form a ligand-antibody-antibody complex followed by its detection using suitable reagents.

Abstract: A specific binding composition comprises a specific binding species and one or more water-soluble proteins or carbohydrates, substantially none of which has a pI greater than about 5. This composition provides improved sensitivity with lower background in diagnostic tests. Preferably, the species is labeled for detection, for example, with an exzyme. The composition can be included with a dye-providing composition in a diagnostic test kit for use in diagnostic methods.

Abstract: A dye-providing composition is useful in various diagnostic assays wherein a peroxidase-labeled specific binding species is used. This composition is substantially free of peroxidase and such labeled species, and comprises an imidazole leuco dye and 4'-hydroxyacetanilide present in an amount up to about 2.5 mmolar. This composition can be included as part of a diagnostic test kit.

Abstract: An aqueous wash solution is buffered to a pH of from about 5 to about 9 and contains at least about 1.5 weight percent of a compound comprising a lower alcohol sulfate anion having from 6 to 10 carbon atoms and an alkali metal or ammonium cation, such as sodium decyl sulfate. This wash solution is useful in a method for the determination of an immunological ligand, and is not prone to crystallization at lower temperatures. Particularly, it is useful for washing the immunological complex formed between the ligand and a receptor molecule therefor. Unreacted materials can be readily separated from the complex by the washing, particularly if the separation is carried out using a filtration membrane in a test device. A test kit for ligand determination comprises the wash solution as well as one or more receptors for the ligand, at least one of which is labeled for detection. This kit is particularly useful for measuring human chorionic gonadotropin (hCG) as an early indicator of pregnancy.

Abstract: An analytical composition, electrode and method are useful for the detection of lithium ions in an aqueous liquid. The lithium ion-selective composition comprises a lipophilic group-substituted 1,10-phenanthroline, a compound capable of solvating the phenanthroline, and a supporting matrix. This composition can be used in a lithium ion-selective electrode as a lithium ion-selective membrane. The electrode can also comprise an internal reference electrode.