Abstract: Certain reducible aromatic and quinone compounds having bulky groups on the carbamate nitrogen atom have improved stability to light. These compounds are useful in analytical compositions, elements and methods, e.g. for assays of bacterial cells. These compounds have suitable substituents that promote the release of phenalenone or benzphenalenone fluorescent dyes at physiological pH.

Abstract: Method for assay of fragments produced by the reaction between the enzyme immunoglobulin A protease and its substrate immunoglobulin A, sub-class 1. IgA1, IgAP and also bacteria which secrete IgAP may be detected. The assay is especially useful in the detection of Neisseria gonorrhea and in the diagnosis of gonorrhea.

Abstract: Derivatives of propranolol which have the following structure: ##STR1## where R is X--(CH.sub.2).sub.n --O, X is NH.sub.2 or COOH, n is 1,2,3,4, or 5, provided that when n is 1, X must be COOH, and R is attached in the 4',5',6',7' or 8' position. The compounds are useful in immunoassay applications to (1) conjugate to a protein carrier in order to prepare antibodies to propranolol and (2) to conjugate to a tracer moiety such as a radiolabeled ligand, an enzyme, an enzyme substrate or a fluorescent dye.

Abstract: A method is disclosed for detecting the occurrence of a binding or complex-forming reaction between specific substances by utilizing the binding reaction to complete an electrical circuit, and then measuring a change in the electrical state of this circuit. In a preferred embodiment, a layer of antigen is coated onto a non-conductive base between a pair of electrically conductive layers superposed on the base. Antibodies which react with the foregoing antigen are treated so that they become bound to fine electrically conductive, metallic particles. The electrically conductive particles having antibody bound thereto are then added to the antigen layer deposited on the base and allowed to react therewith. Electrically conductive particles are thereby bound to the base due to the binding reaction between the antigen and antibody to thereby form aggregates of electrically conductive particles which bridge the electrically conductive layers and complete the circuit.

Abstract: A nucleic acid probe capable of participating in a chemiluminescent reaction comprising a defined nucleic acid sequence, the sequence being linked to any one ofa. a chemiluminescence precursor,b. a chemiluminescence enhancer, andc. an enzyme the remaining two of (a), (b) and (c) not linked to the sequence being in a mixture of the linked sequence. A method for determining a particular single stranded polynucleotide sequence in a test medium, comprising the steps of:(a) combining the test medium with a polynucleotide probe having a base sequence substantially complementary to the sequence to be determined,(b) labeling either the resulting hybrids or probe which has not hybridized with the sequence to be determined with one of the participants in an enhanced chamiluminescent reaction involving a chemiluminescent precursor, an enzyme, an oxidant, and a chemiluminescence enhancer,(c) initiating such chemiluminent reaction with the labeled hybrid or probe, and(d) detecting the resulting light emission.

Abstract: Methods for attaching one component of a ligand-anti-ligand pair onto a solid phase surface. The component may be attached to a photoactivatable cross-linker capable of coupling the component to a colloidal medium coating the surface or alternatively, the component may be coupled to a bead and held in place against the surface by an overlay of the colloidal media having voids and spaces smaller than the diameter of the particle but large enough to permit diffusion of the other of the ligand-anti-ligand pair to be detected.

Abstract: A method of detecting activated T-cells in a population of cells, the method involving determining intracellular calcium ion concentration or intracellular pH in the cells, a calcium ion concentration two-fold or greater above that of resting T-cells, or a pH increase of over 0.2 pH units, indicating activation.

Abstract: Improved fluorescent labels comprise a fluorescent rare earth chelate incorporated into a polymeric particle derived from a loadable latex. The polymer comprises: (a) from about 50 to about 96 weight percent of recurring units derived from a hydrophobic ethylenically unsaturated polymerizable monomer, (b) from about 2 to about 30 weight percent of recurring units derived from a nonionic hydrophilic ethylenically unsaturated polymerizable monomer, and (c) from about 2 to about 20 weight percent of recurring units derived from an anionic ethylenically unsaturated polymerizable monomer containing at least one solubilizing group. The labels of this invention have greatly improved stability in aqueous solutions and do not prematurely agglomerate during storage. They can be attached to any of a variety of physiologically reactive species to provide labeled species, and are particularly useful in specific binding assays.

Abstract: The invention relates to new quinoline derivatives of the formula: ##STR1## wherein R stands for C.sub.2 H.sub.5, C.sub.2 H.sub.4 F, CH.sub.2 --O--CH.sub.2 --CH.sub.2 OH, ##STR2## to a process for their preparation comprising reacting, for 12-24 hours, at 70.degree.-95.degree. C., in dimethylformamide, the 1,4-dihydro- 3-ethoxycarbonyl- 6,8- difluoro-4-oxo-quinoline with an excess of RX (2-5 mol of RX for one mol of quinoline), in the presence of K.sub.2 CO.sub.3 and subsequently hydrolyzing the obtained 3-ester by HCl under reflux conditions and to pharmaceutical compositions comprising at least one 1,4-dihydro- 3-carboxy- 6,8-difluoro- 1-R-4-oxo-quinoline derivative in admixture with a pharmaceutically acceptable diluent or carrier.

Abstract: The specification discloses a method and apparatus for the assay of salicylate (or a derivative thereof) comprising a conducting body having at a surface thereof an enzyme capable of catalyzing the conversion of salicylate (or a derivative thereof) to a catechol whereby said catechol is subject to direct electrochemical measurement as it oxidizes at said surface to generate a current as a measure of the reaction taking place and thereby of the concentration of salicylate at said surface. The method typically comprises the steps of;(a) treating a liquid sample suspected of containing salicylate or a derivative thereof with an enzyme capable of catalyzing the conversion of salicylate or a derivative thereof into a catechol, and,(b) measuring the concentration of catechol in the treated sample by direct electrochemistry.

Abstract: A method of detecting and localizing nucleic acids on polyamide supports which comprises contacting said supports with a suspension of colloidal metal particles whereupon the metal particles bind to the polyamide support and form a colored background against which the location where nucleic acids are present become visible as lighter spots. The method enables the mere qualitative localization of the nucleic acids and the quantitative determination thereof following art-known procedures.

Abstract: Fluorescent antigen conjugates are provided comprising antigens covalently bonded to at least one 2,7-dialiphatic substituted-9-phenyl-6-hydroxy-3H-xanthen-3-one, wherein the 1- and 8-positions are unsubstituted. Also provided are novel fluorescent compounds absorbing at wavelengths in excess of 500 nm, having active functionalities for linking to the antigen. Finally, methods are provided for analyzing antigens in serum, whereby serum interference is avoided.

Abstract: A method for producing monoclonal antibodies to a trichothecene mycotoxin which are used in a test kit and method of testing are described. The method for producing the monoclonal antibodies uses repeated administration, preferably subcutaneously of a trichothecene polypeptide to a murine and production of a hybridoma to generate the monoclonal antibodies. Trichothecenes are detected in foods and the like using the test kit and method.

Abstract: 1,10-phenanthroline-2,9-dicarboxylic acid and novel derivatives thereof such as 4,7-diphenyl-1,10-phenanthroline-2,9-dicarboxylic acid and 4,5,9,14-tetraaza-(1,2,3,4)-dibenzanthracene-3,5-dicarboxylic acid can be coupled to proteins through coupling groups to form conjugates which form higly fluorescent chelates in the presence of lanthanide salts. Derivatives of the above acids reactive toward proteins can be readily manufactured by relatively simple synthetic routes, and are useful in fluorescent immunoassay.

Abstract: A method for detection of DNA sequences. In the method, chromatin (comprising protein and DNA) is contacted with a cross-linking agent for the protein of the chromatin to provide a substantially rigid chromatin particle. The DNA of the chromatin particle is then subjected to treatment to cause a separation of the individual DNA strands into single stranded DNA. Preselected sequences of the single stranded DNA are then contacted with a complementary polynucleotide probe specific for the DNA sequence of interest. The polynucleotide probe is marked with a fluorescent label thereby labelling a target sequence of DNA in the chromatin particles. The fluorescently tagged DNA sequences are then detected by subjecting the polynucleotide probe to a suitable light source and detecting the light emitted by the fluorescent label so as to identify the preselected DNA sequence.

Abstract: Fluorescent reagents useful as opioid receptor probes. Opioids labeled at the 3 position with fluorescers are useful in various in vivo and in vitro methods for the detection and quantification of receptor sites in tissue cells and subcellular particles.

Abstract: Novel arginine derivatives represented by the general formula ##STR1## wherein R.sup.1 stands for a naphthalenesulfonyl, a naphthalenecarbonyl, a 1,2,3,4-tetrahydronaphthalenesulfonyl, a 1,2,3,4-tetrahydronaphthalenecarbonyl, a dioxa b-6,7-naphthalenesulfonyl, a dioxa b-6,7-naphthalenecarbonyl, a 1,2,3,4-tetrahydro-8-quinolinesulfonyl, a 1,2,3,4-tetrahydro-8-quinolinecarbonyl, a dibenzofuransulfonyl, a dibenzofurancarbonyl, a fluorenesulfonyl, a fluorenecarbonyl, a dibenzothiophenesulfonyl or a dibenzothiophene, and R.sup.2 stands for a piperidino or a piperazino are disclosed. These arginine derivatives and their pharmaceutically acceptable salts have trypsin-inhibiting activity and useful as a pancreatitis remedy.

Abstract: A method is disclosed for determining the presence of a member of a specific binding pair ("sbp member") consisting of ligand and its homologous receptor in a sample suspected of containing the sbp member. The method comprises combining in an assay medium the sample and an opaque particle capable of agglutinating in the presence of the sbp member. The opaque particle has a particle size of from about 0.2 to 5.0 microns. Next, the assay medium is irradiated with light having a wavelength of from about 350 to 2000 nm, and the optical density of the assay medium is measured. A change in optical density indicates the presence of the sbp member in the sample. The method has particular application in the determination of an antibody in a sample, particularly an autoantibody, such as, for example, rheumatoid factor.

Abstract: A novel nucleic acid, arabinonucleic acid, is provided as a probe in nucleic acid assays. The arabinose moiety of the probe can be detected with anti-arabinose antibody-label conjugates.

Abstract: A process for the purification of caffeine which comprises carrying out the following steps in any order;(a) recrystallization of caffeine from an aqueous alkaline solution of caffeine containing a reducing agent and(b) extraction of the caffeine from an aqueous alkaline solution of caffeine with a substantially water-immiscible solvent which is liquid under the conditions of the process.