Abstract: The signal generated in a specific binding assay wherein a peroxidase label is used to detect the resulting specific binding complex on a microporous filtration membrane can be modulated by contacting the signal forming reagents with a buffered solution of a hydroxamic acid or acyl hydrazine having the structureR--CO--NH--R'or an equivalent salt thereof, wherein R is aryl of 6 to 10 carbon atoms in the aromatic nucleus, alkyl of 1 to 7 carbon atoms or cycloalkyl of 5 to 10 carbon atoms in the ring, and R' is hydroxy or amino. This solution can be provided in a diagnostic test kit for use in various methods to detect a specific binding ligand. The result is improved signal stability and lowered background after the use of a high pH wash solution in the assay.

Abstract: A method has been developed for determining microorganisms associated with periodontal diseases which is highly sensitive and shows very low background and cross-reactivity among various closely related antigens. Antigen is extracted at relatively high pH, and either before or immediately after extraction, the antigen-containing specimen is mixed with a blocking composition having at least about 0.2 weight percent of a non-immunoreactive blocking protein. The pH of the resulting mixture is kept high when contacted with the antibodies specific to the antigen of interest. The compositions and components needed for the assay can be supplied in a diagnostic test kit.

Abstract: An aqueous wash composition has been found useful in methods for determination of specific binding ligands. The composition is buffered to a pH of less than or equal to 6 or greater than or equal to 9. It also includes as its essential component at least about 0.1 weight percent of an anionic surfactant which is represented by the formula:[A-SO.sub.3+y ].sup.-(1+y) [X.sup.+m ].sub.nwherein A is a hydrocarbon having a molecular weight of at least about 180, X.sup.+m is hydrogen or a monovalent or divalent cation, m is 1 or 2, is 0 or 1, and n is 1 or 2 provided that m and n are not both 2. Optionally and preferably, the wash composition also includes a nonimmunoreactive protein. This wash composition is particularly useful in methods for determination of microorganisms associated with periodontal diseases. Such methods can be of a variety of formats, but immunometric assays are particularly useful. The wash composition can be included as part of a diagnostic test kit.

Abstract: An aqueous wash composition has been found useful in methods for determination of specific binding ligands. The composition is buffered to a pH of less than or equal to 6 or greater than or equal to 9. It also includes as its essential component at least about 0.1 weight percent of an anionic surfactant which is represented by the formula:[A-SO.sub.3+y ].sup.-(1+y) [X.sup.+m ].sub.nwherein A is a hydrocarbon having a molecular weight of at least about 180, X.sup.+m is hydrogen or a monovalent or divalent cation, m is 1 or 2, y is 0 or 1, and n is 1 or 2 provided that m and n are not both 2. Optionally and preferably, the wash composition also includes a nonimmunoreactive protein. This wash composition is particularly useful in methods for determination of microorganisms associated with periodontal diseases. Such methods can be of a variety of formats, but immunometric assays are particularly useful. The wash composition can be included as part of a diagnostic test kit.

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: Antigens from chlamydial organisms in specimens can be rapidly and sensitively determined using a polyamide microporous membrane which has surface hydroxy groups. This determination is accomplished by contacting extracted antigen with the polyamide microporous membrane for a sufficient time for the antigen to bind to the membrane. Antigen bound to the membrane is contacted with chlamydial antibody so as to form an immunological complex on the membrane. The presence of the complex on the membrane in then determined as a measure of the amount of chlamydial antigen present in the specimen. The use of this particular membrane improves reagent keeping and reduces background in the assay.