Abstract: Novel monoclonal antibodies to an aflatoxin B.sub.1 and G.sub.1 in a test kit and used in a method of testing are described. The method for producing the monoclonal antibodies uses repeated administration of aflatoxin B.sub.1 or the related analog compound as a 1-position polypeptide to a murine and production of a hybridoma to generate the novel monoclonal antibodies. The novel antibodies have limited cross-reactivity to aflatoxins B.sub.2, G.sub.2 and M.sub.1. Aflatoxin B.sub.1 or aflatoxin G.sub.1 are detected in foods and the like using the test kit and method.

Abstract: Electrochemical detection of mediator level is employed in a method of assay using a redox enzyme and redox substrate to detect conversion to an effective mediator by an assay enzyme label of a compound which is non-mediating under the assay conditions.

Abstract: The present invention provides a process for the preparation of an immuno-reactive, porous carrier material by application of a solution of a first reaction component of an immuno-reaction and of a solution of a second component of an immuno-reaction coprecipitating therewith, incubation of the carrier material impregnated with the solutions for the immuno-precipitation, optional washing and subsequent drying of the impregnated carrier material, wherein a solution of both components of the immuno-reaction is prepared, which solution contains an inhibitor for the immuno-precipitation, the carrier material is impregnated with this solution and then the immuno-precipitation is initiated by removal of the inhibitor or by removal of the inhibiting action.

Abstract: A diagnostic reagent is disclosed which is capable of binding to a target nucleotide sequence which is bound to a labeled polynucleotide in a target binding region which is at least partially co-extensive with the target binding region in the probe polynucleotide which is capable of binding to the target nucleotide sequence. A method is disclosed in which the reagent is contacted with a sample and with a capturing polynucleotide under conditions such that target nucleotide which may be present in the sample binds to the probe polynucleotide and displaces labeled polynucleotide from the reagent complex, and the capturing polynucleotide binds selectively to the displaced labeled polynucleotide in the region of the labeled polynucleotide that had been bound to the probe polynucleotide. Determination of the displaced nucleotide gives a value which is a function of the presence and concentration of target nucleotide in the sample.

Abstract: A method for immunoassay for a ligand suspected to be present in a fluid includes use of an enzyme, a metal ion catalyst for an indicator reaction and a blocked modulator for the catalyst. Ligand present in the fluid binds to an antiligand. The resulting bound fraction activates the enzyme to unblock the modulator. The free modulator activates or inhibits the catalyst thereby modulating the rate of an indicator reaction between a substrate and a redox reagent. The presence of absence of the ligand in the fluid is indicated by a signal, such as a color change or a rate of color change, consequent to the indicator reaction. The invention includes a kit of materials useful for performing the method of the invention.

Abstract: The invention concerns a composition of fragments of DNA utilizable as a probe for the detection of specific micoorganism, notably Legionella, in environments which contain them. These compositions are obtained from the whole genomes of the microorganisms to be detected, after fragmentation of these genomes, particularly by using a restriction enzyme, and eliminating those sequences of the genomic DNA which are susceptible to being transcribed to ribosomal RNA.

Abstract: Hybrid cell line for production of monoclonal antibody to an antigen found on approximately 95% of normal human thymocytes. The hybrid is formed by fusing splenocytes from immunized CAF.sub.1 mice with P3X63Ag8U1 myeloma cells. Diagnostic and therapeutic uses of the monoclonal antibody are also disclosed.

Abstract: The invention relates to a process for the microbiological preparation of aldose-1-epimerase by cultivating microorganisms in a nutrient medium and release of the enzyme from the cells, which process is characterized in that microorganisms of the genus Acinetobacter are used.

Abstract: A microbiological culture test process for detecting the presence of nitrate-reducing microorganisms in an inoculum sample, which comprises(a) culturing a microorganism to be tested in the presence of adequately nitrite-free nitrate, for a period sufficient to allow reduction of nitrate by any microorganism (if present) that has the capacity to reduce nitrate to nitrite, (e.g. 1-6 hours);(b) exposing the culture medium after culture to (diazotizing) acid conditions in the presence of an amino-containing fluorophor thereby to cause diazotization of the fluorophor to the extent of any nitrite present in the medium to form a diazonium derivative (or further reaction product thereof) which is substantially less fluorescent (or fluoresces at a substantially different wavelength) than said amino-containing fluorophor, and(c) assessing the fluorescence of the culture medium as treated by step (b), thereby to show a reduction in fluorescence in the presence of a nitrate-reducing microorganism.

Abstract: A probe is attached to a stock support to which is bound a single-stranded polynucleotide by hybridizing both the probe and the bound polynucleotide to a connecting strand with which they are both complementary and then ligating an end of the bound polynucleotide and the probe. After denaturation, the probe remains attached to the support by way of the bound polynucleotide. A target polynucleotide is then hybridized with the support-bound probe and with a labelled probe to provide a detectable hybridization complex.

Abstract: An RNA signal strand is displaced from a probe strand by a target nucleotide sequence. Without separation, a digestion enzyme selective for displaced RNA, e.g., a polynucleotide phosphorylase, digests the displaced RNA to nucleoside phosphates including ADP. The digestion products are detected, e.g. by phosphorylating the ADP to ATP and detecting the ATP by bioluminescence.

Abstract: Fluorogenic indicator compounds responsive to the presence of hydrogen peroxide and methods and test compositions for determining hydrogen peroxide in a test sample. Preferred indicator compounds are 3,4-dihydrocoumarin derivatives and 3,4-dihydro-2-quinolone derivatives, especially those having a dialkylamino group at the 7-position. Such particularly preferred compounds are of the formula: ##STR1## wherein R.sup.1 is hydrogen, cyano, or --COOR.sup.6, --CONHR.sup.6 or --CON(R.sup.6).sub.2 where R.sup.6 is hydrogen, alkyl, alkenyl, or aryl; R.sup.3 and R.sup.4 are lower alkyl; and Y is .dbd.0 or .dbd.N--R.sup.5 where R.sup.5 is hydrogen or lower alkyl. The indicator compounds yield highly fluorescent products upon oxidation by hydrogen peroxide in the presence of a peroxidatively active substance and are useful in analytical systems which generate hydrogen peroxide in response to an analyte under determination in a test sample.

Abstract: The present invention discloses a method and a kit for monitoring human exposure to genotoxic agents. The method comprises an immunoassay for detecting in human serum specific antibodies against DNA adducted to an agent suspected of being genotoxic. A kit comprising various components for performing the assay is also disclosed.

Abstract: A new and improved cell assay has been developed for mutagens and potential carcinogens to precisely identify the predominant type of mutation(s) each such compound induces in the DNA of cells. The test utilizes, for example, a selectable genetic marker such as adenine phosphoribosyltransferase (APRT) which is now extensively characterized on the DNA, protein and cellular phenotype levels. Specific mutations such as transitions, transversions, point insertions or point deletions are engineered at specific known sites in a mouse APRT gene deduced from the determined gene sequence, such that the gene cannot be properly expressed. These mutant genes are then introduced into non-reverting APRT deficient mammalian cells. These hybrid constructs represent the basic test medium for detection of mutagenic activity. The tester cells are treated with mutagens known to preferentially induce specific DNA mutations in mammalian cells.

Abstract: A highly sensitive quantitative assay method for a component which is 3.beta.-hydroxysteroid or 3-ketosteroid, in a specimen to be assayed, comprising causing this component in the specimen to take part in the cycling reaction ##STR1## and measuring a detectable change in the reaction system. There is thus provided a 3.beta.-hydroxysteroid - 3-ketosteroid cycling reaction using 3.beta.-hydroxysteroid oxidase, which consumes O.sub.2 and generates H.sub.2 O.sub.2 and 3-ketosteroid, with a substrate of 3.beta.-hydroxysteroid, or 3.beta.-hydroxysteroid dehydrogenase, which consumes reduced NAD(P) and generate NAD(P) and 3.beta.-hydroxysteroid, with a substrate of 3-ketosteroid. Example of specimens are specimens which contain 3-hydroxysteroid or 3-ketosteroid, or which liberate or generate such a component.

Abstract: An analytical element for quantitative analysis of analyte contained in a body fluid or the like, which has at least one reagent layer comprising a reactive reagent and a binder, characterized in that a portion or whole of the binder is a polycarboxylic acid carrying a nonionic surface active agent attached through ester linkage to at least a portion of the carboxyl groups contained therein.

Abstract: Radiodinated and non-radiodinated 16.alpha.-iodo- and 17.alpha.-(2-iodovinyl)-19-nortestosterones are prepared and are used in progesterone receptor assays.

Abstract: The invention relates to novel monoclonal antibodies having a high affinity for human renin, derivatives thereof, processes for the preparation of these antibodies and their derivatives, hybridoma cell lines that produce these antibodies, and to processes for the preparation of said hybridoma cells lines. The monoclonal antibodies according to the invention and their derivatives can be used for the qualitative and quantitative determination of human renin and structurally similar renin, for the purification of human renin and structurally similar renin and for the treatment of high blood pressure and cardiac insufficiency.

Abstract: A human endogenous retrovirus-related Mv-75,000 protein, containing the decapeptide sequence Glutamic Acid-Asparagine-Proline-Serine-Glutamine-Phenylalanine-Tyrosine-Glutamic Acid-Arginine-Leucine, a synthetic undecapeptide Sp-23 based on the decapeptide, and specific polycolonal and monoclonal antibodies and specific nucleic acid probes are used as specific reagents for the detection and treatment of tumors such as renal cell adenocarcinoma and choriocarcinoma, among others, and placental disorders including blighted ova, hydatiform and destructive moles.

Abstract: Antibodies which form immune complexes with human native prothrombin only, in the presence of mixtures of human native prothrombin and human abnormal prothrombin as well as antibodies which form antibody antigen complexes with human abnormal prothrombin in the presence of such mixtures have been obtained. Immunoassay techniques are used for qualitative and quantitative determinations of these antigens in human plasma or serum. Unique methods of obtaining the antibodies are described including obtaining antibodies to native prothrombin by dissociation of antigen antibody complexes formed in the presence of calcium ions with a material having a greater affinity constant for binding with calcium ions than does prothrombin. Dissociation of the complex in this manner yields human native prothrombin antibodies which are specific and non-reactive with human abnormal prothrombin.