Abstract: A test device, method, and indicators for the colorimetric determination of formaldehyde neutralization in an aqueous solution initially containing formaldehyde are provided. Formaldehyde is neutralized by reaction with sulfite ion, where the sulfite ion is provided by dissolving a sulfite-containing compound or neutralizer, such as sodium sulfite, sodium bisulfite, or a mixture thereof, into the aqueous solution containing formaldehyde. The indicators may include dyes capable of exhibiting a color change in the presence of an excess amount of sulfite ion over the amount of formaldehyde in the aqueous solution. A test medium includes the dye, where the test medium may be a test strip impregnated with one of the indicator dyes and optionally a buffer, or a liquid solution containing the dye.

Abstract: A rapid method and easy to use unitized test device is disclosed for determining the presence of Helicobacter pylori in a biological tissue specimen by detecting the presence of urease in the tissue. The system basically utilizes a multilayer test device for separating and optimizing the various reactions involved, i.e. the urease in the specimen with a substrate and the ammonia generated thereby with an indicator element.

Abstract: A rapid method and easy to use unitized test device is disclosed for determining the presence of Helicobacter pylori in a biological tissue specimen by detecting the presence of urease in the tissue. The system basically utilizes a multilayer test device for separating and optimizing the various reactions involved, i.e. the urease in the specimen with a substrate and the ammonia generated thereby with an indicator element.

Abstract: A nucleic acid hybridization assay employing an immobilized or immobilizable polynucleotide probe selected to form DNA.RNA or RNA.RNA hybrids with the particular polynucleotide sequence to be determined. Resulting hybrids are detected by binding of an antibody reagent, preferably labeled with a detectable chemical group, selective for binding the hybrids in the presence of the single stranded sample and probe nucleic acids. No immobilization or labeling of sample nucleic acids is necessary and hybridization can be performed entirely in solution.

Abstract: A monoclonal antibody specific for DNA.multidot.RNA duplexes, particularly DNA.multidot.RNA heteropolymer duplexes, characterized by having cross-reactivity for binding to single- or double-stranded DNA or RNA as measured by competitive immunoassay of less than about 1:1000, and preferably less than 1:10,000, and an affinity for DNA.multidot.RNA heteropolymer duplexes greater than 10.sup.9 L/mole. The monoclonal antibody is prepared by conventional somatic cell hybridization techniques wherein the host animal is preferably immunized with an immunogen comprising a random DNA.multidot.RNA heteropolymer. The antibody, particularly in a labeled form, is useful in the specific detection of DNA.multidot.RNA duplexes in a test medium such as a nucleic acid hybridization assay mixture.

Abstract: Immobilization of nucleic acids, e.g., DNA and RNA, by contact with a solid support comprising nylon having amide groups that have been derivatized to amidine residues. Derivatization of the nylon support can be accomplished by treatment with an alkylating agent such as a trialkyloxonium salt under anhydrous conditions followed by reaction with an amine. The immobilized nucleic acid is particularly useful as an immobilized probe in hybridization assays to detect specific polynucleotide sequences in a test sample.

Abstract: Immobilization of nucleic acids, e.g., DNA and RNA, by contact with a solid support comprising nylon whose amide groups have been partially solvolyzed. Solvolysis of the nylon support can be accomplished by treatment with an alkylating agent such as a trialkyloxonium salt under anhydrous conditions followed by addition of water. The immobilized nucleic acid is particularly useful as an immobilized probe in hybridization assays to detect specific polynucleotide sequences in a test sample.

Abstract: The reactant advantageously is an enzymatic reactant such as an enzyme substrate or coenzyme. The activity of the conjugated reactant as a constituent of a predetermined reaction is affected by reaction between the specific binding substance in the conjugate and a specific binding counterpart thereto. The presence of a ligand in a liquid medium may be determined using competitive or displacement binding or sequential saturation techniques wherein the specific binding substance in the conjugate is the ligand or a specific binding analog thereof, or using a direct binding technique wherein the specific binding substance is a specific binding partner of the ligand. The effect of the specific binding reaction on the activity of the conjugated reactant is related to the presence or amount of the ligand in the liquid medium tested.

Abstract: A nucleic acid hybridization assay involving a labeled probe and formation of a hybrid having epitopes for an antibody reagent. The label provides a detectable response which is measurably different when the labeled probe is comprised in a hybrid that is bound by the antibody reagent compared to when not comprised in such a hybrid. Particularly useful antibody reagents are antibodies such as anti-DNA.RNA, anti-RNA.RNA and antibodies to intercalated duplexes which do not bind substantially to single stranded nucleic acids. Modulation of the label response can be accomplished in a variety of ways such as by steric inactivation or hindrance or by labeling the antibody reagent with a second label which interacts with the first label. The assay is particularly advantageous because no separation of hybridized and unhybridized probe is required.

Abstract: A test composition, device, and method for their use in a homogeneous specific binding assay which employs a substance having reactant activity, i.e., a reactant, as a labeling substance in the detection of a ligand in a liquid medium. The test composition and device comprise a conjugate formed of a specific binding substance coupled to the reactant. The reactant advantageously is an enzymatic reactant such as an enzyme substrate or coenzyme. The activity of the conjugated reactant as a constituent of a predetermined reaction is affected by reaction between the specific binding substance in the conjugate and a specific binding counterpart thereto. The presence of a ligand in a liquid medium may be determined using competitive or displacement binding or sequential saturation techniques wherein the specific binding substance in the conjugate is the ligand or a specific binding analog thereof, or using a direct binding technique wherein the specific binding substance is a specific binding partner of the ligand.

Abstract: An improved heterogenous specific binding assay method which employs a substance having reactant activity, i.e., a reactant, as a labeling substance in the detection of a ligand in a liquid medium. The method is carried out using reagent means which comprises, as its labeled constituent, a conjugate formed of a specific binding substance coupled to the reactant. The reactant advantageously is an enzymatic reactant such as an enzyme substrate or coenzyme. The activity of the conjugated reactant as a constituent of a predetermined reaction system is utilized as means for monitoring the extent of binding of the labeled constituent in conventional heterogenous specific binding assay schemes. The presence of a ligand in a liquid medium may be determined following conventional competitive binding manipulative techniques.

Abstract: A propranolol immunogen comprising an unsubstituted hydroxypropylamine precursor of propranolol coupled through a bis-imidate linking group to an immunogenic carrier material. The immunogen is useful to stimulate the production of antibodies which recognize propranolol and can perform as reagents in immunoassays to determine propranolol.

Abstract: An improved immunoassay method, reagent means, and test kit for determining an iodothyronine, e.g., thyroxine (T-4), in a biological fluid, usually serum or plasma, wherein fenclofenac and related phenylacetic acids, or salts thereof, are employed as novel blocking agents for the binding of iodothyronines to thyroxine binding protein (TBP). The present invention is particularly advantageous as applied to homogeneous competitive binding iodothyronine immunoassays wherein a spectrophotometric response is generated in the assay reaction mixture at a wavelength greater than about 300 nm, the blocking agents of the present invention having been found to have no substantial absorbance at wavelengths above 300 nm. Such homogeneous immunoassays include those which employ labels such as fluorescers, enzyme substrates, enzyme prosthetic groups, enzymes, and enzyme inhibitors.

Abstract: An improved specific binding assay method and reagent for determining a ligand in a liquid medium employing, as an enzyme-cleavable substrate label, a residue having the formula:G--D--Rwherein G is a glycone, D is a dye indicator moiety, and R is a linking group through which the label residue is covalently bound to a binding component of a conventional binding assay system, such as the ligand, an analog thereof, or a specific binding partner thereof. The monitored characteristic of the label is the release of a detectable product, usually a fluorogen or chromogen, upon enzymatic cleavage of the glycosidic linkage between the glycone and the dye indicator moiety. The assay method may follow a homogeneous or heterogeneous format. The preferred glycone is a .beta.-galactosyl group and the preferred dye indicator moiety is an umbelliferone residue.

Abstract: Immunogen conjugates comprising N-aminoalkyl derivatives of iodothyronines, e.g., thyroxine and its lower alkyl esters, coupled to an immunogenic carrier material, and antibodies raised against such immunogen conjugates.

Abstract: A homogeneous specific binding assay which employs a substance having reactant activity, i.e., a reactant, in a chemiluminescent reaction as a labeling substance in the detection of a ligand in a liquid medium. The assay employs a conjugate formed of a specific binding substance coupled to the chemiluminescent reactant. The activity of the conjugated reactant as a constituent of the chemiluminescent reaction is affected by reaction between the specific binding substance in the conjugate and a specific binding counterpart thereto. The presence of a ligand in a liquid medium may be determined using competitive or displacement binding or sequential saturation techniques wherein the specific binding substance in the conjugate is the ligand or a specific binding analog thereof, or using a direct binding technique wherein the specific binding substance is a specific binding partner of the ligand.

Abstract: A heterogeneous specific binding assay which employs a substance having reactant activity, i.e., a reactant, in a chemiluminescent reaction as a labeling substance in the detection of a ligand in a liquid medium. The method is carried out using reagent means which comprises, as its labeled constituent, a conjugate formed of a specific binding substance coupled to the chemiluminescent reactant. The activity of the conjugated reactant in the chemiluminescent reaction, i.e., the production of light, is utilized as means for monitoring the extent of binding of the labeled constituent in conventional heterogeneous specific binding assay schemes. The presence of a ligand in a liquid medium may be determined following conventional competitive binding manipulative techniques.

Abstract: Chemiluminescent-labeled conjugates of the formula: ##STR1## wherein one of R.sup.1 and R.sup.2 is hydrogen and the other is -NR.sup.3 R.sup.4 ; R.sup.3 is hydrogen or straight chain alkyl containing 1-4 carbon atoms and R.sup.4 is ##STR2## wherein n=1-3 and L(CO-- is the ligand or analog bound through an amide bond. Intermediates produced in the synthesis of such conjugates are also disclosed.

Abstract: N-Aminoalkyl derivatives of iodothyronines, e.g., thyroxine and its lower alkyl esters, immunogen conjugates comprising the derivatives coupled to an immunogenic carrier material, and antibodies raised against such immunogen conjugates.

Abstract: Amino-functionalized phthalhydrazide intermediates of the formula: ##STR1## wherein one of R.sup.5 and R.sup.6 is hydrogen and the other is --NR.sup.7 R.sup.8 ; R.sup.7 is hydrogen or straight chain alkyl containing 1-4 carbon atoms and R.sup.8 is ##STR2## wherein n=1-3. The compounds are intermediates in the synthesis of chemiluminescent-labeled conjugates which are useful as reagents in specific binding assays for determining ligands or their specific binding partners in liquid media.