Abstract: A method of assay for isotopically exchangeable analytes is disclosed. Analytes are labeled by enzymatic exchange of a hydrogen atom of the analyte and a deuterium or tritium atom. Preferably, analytes are labeled by reaction with an oxidant, a reducing agent which contains a deuterium or tritium atom, and an enzyme capable of catalyzing the reversible exchange of a hydrogen atom between the analyte, the oxidant, and the reducing agent. Kits for conveniently performing the assay methods are also disclosed.

Abstract: A kit for inactivating interfering binding proteins in a immunoassay for a member of a specific binding pair (sbp). The method comprises including in an assay medium containing a sample suspected of containing an sbp member and an interfering binding protein an effective amount of a water soluble compound having two substituted or unsubstituted phenyl groups linked to a common atom. When the sbp member or its sbp partner has two phenyl groups linked to a common atom, the compound has a number of-groups other than hydrogen attached to the phenyl groups and the atom that differs by at least two from the number of such groups on the sbp member. When the sbp member or its sbp partner has two phenyl groups linked to a common atom and the binding protein is not an antibody, the compound has only one group other than hydrogen attached to a phenyl group or the common atom.

Abstract: A method is disclosed for detecting the presence of a target nucleotide sequence in a polynucleotide. The method comprises hybridizing a first nucleotide sequence and a second nucleotide sequence to non-contiguous portions of a target nucleotide sequence, covalently attaching the first and second sequences when they are hybridized to the target sequence, and determining the presence of covalently attached first and second sequences. The presence of the covalently attached first and second sequences is related to the presence of the target nucleotide sequence. The invention may be applied to target nucleotide sequences in DNA or RNA. Specific target nucleotide sequences of interest will frequently be characteristic of particular microorganisms, viruses, viroids, or genetic characteristics, including genetic abnormalities.

Abstract: A device is disclosed for conducting an assay method. The device comprises a housing, means enclosed in the housing for capturing a member of a specific binding pair in a zone and for allowing liquid to be transported by capillary action away from the zone, one or more self-contained liquid reagents enclosed in the housing for conducting an assay method for the determination of an analyte in the sample, and means in the housing for introducing the sample into the device. Preferably, the self-contained reagents are liquid reagents which are contained in a breakable container. The device of the invention finds use in assay methods for the determination of an analyte in a sample suspected of containing the analyte. Kits for conducting an assay method are also disclosed.

Abstract: Compounds and methods are disclosed for reversibly aggregating particles suspended in a liquid medium. The method comprises combining the liquid medium containing the particles with a polyionic polymer capable of aggregating the particles under conditions suitable for such aggregation. Thereafter, the particles are contacted with a chemical reagent capable of cleaving the polyionic polymer under conditions sufficient to reverse the aggregation. Optionally, magnetic particles are added to the liquid medium in the present method under conditions for non-specific binding and the medium including the aggregates is subjected to a magnetic field gradient to separate the aggregates from the medium. The compounds of the present invention are polyions. The aggregation of the particles is reversible upon contact with chemical agents which cleave at least some of the bonds within the polyionic polymer.