Abstract: Compounds having detergent properties are disclosed. When a modifying reagent is brought into contact with these compounds, the detergent properties are decreased. These compounds are useful, for example, as solubilizing agents for microbial antigens and/or antibodies and for reversibly wetting hydrophobic surfaces. Accordingly, methods are disclosed for increasing the hydrophilic properties of a material, such as a microbial antigen and/or antibody, the methods generally comprising the steps of contacting the material with the compound having detergent properties and a modifiable group, and modifying the compound with a modifying reagent. Kits are also disclosed for use in accordance with this methodology.

Abstract: Disclosed are devices and methods for interrupting capillary flow of a liquid between two pieces of bibulous material which, prior to actuation, are in a capillary flow relationship to each other. In particular, the capillary flow relationship of two pieces of bibulous material is interrupted by utilizing a liquid expandable piece of bibulous material.

Abstract: Carbonyl derivatives of acetaminophen are provided for use in homogeneous enzyme immunoassays for acetaminophen. The derivatives are conjugated to antigenic substances for the preparation of antisera specific to acetaminophen, and to enzymes for the preparation of enzyme conjugates which compete with acetaminophen for antibody binding sites in a typical assay.

Abstract: Disclosed is a novel microscope slide. The slide of this invention is a plastic microscope slide which is optically opaque and substantially non-fluorescent. The slide of this invention has particular utility in epi-fluorescent microscopy.

Abstract: Conjugates of salicylic acid and certain poly(amino acids), which are either antigenic or enzymes, are provided. Antibodies raised against the antigenic poly(amino acids) and the enzyme conjugates are used as reagents in immunoassays.

Abstract: 2-methyl-4-hexene- and 3-methyl-5-heptene-1,2-diol derivatives are disclosed together with methods for preparing such derivatives. Where the derivative is a 2-methyl-4-hexene- or 3-methyl-5-heptene-1,2-diol conjugated to a label, the conjugates are useful in immunoassays. Where the 2-methyl-4-hexene or 3-methyl-5-heptene-1,2-diol is conjugated to an immunogenic carrier, the conjugates may be employed as an immunogen for use in the preparation of antibodies. The label conjugate and the antibodies can be utilized in an immunoassay for the determination or detection of cyclosporin in a sample suspected of containing cyclosporin.

Abstract: Methods and compositions are provided for assays involving members of a specific binding pair ("sbp members") and members of a signal producing system ("sps members"). The signal producing system is capable of producing a detectible signal in relation to the presence or amount of an analyte in a sample suspected of containing the analyte. Exemplary of sps members are enzymes and enzyme substrates, which react with each other to produce a signal. The improvement of the present invention comprises temporarily delaying the production of the signal without subsequent reagent addition. The delay can be achieved by employing an inhibitor which can be an alternate substrate for the enzyme or a compound which reacts with the product of the enzyme and its substrate in an effective amount.

Abstract: A method and device for determining the presence of an analyte in a sample suspected of containing the analyte is disclosed. The method involves contacting a test solution containing the sample, an antibody for the analyte, and a conjugate of the analyte and a label with a contact portion of a piece of bibulous material capable of being traversed in at least one direction by the test solution through capillary action. The bibulous material contains a first receptor capable of binding to said conjugate. The first receptor is non-diffusively bound to a situs on the bibulous material separate from the contact portion. The bibulous material further contains a second receptor capable of binding the antibody to the analyte between the situs and the contact portion. The second receptor is non-diffusively bound to the bibulous material. At least a portion of the test solution is allowed to traverse the bibulous material by capillary action and thereby contact the situs.

Abstract: A method and device for determining the presence of an analyte in a sample suspected of containing the analyte are disclosed. The method involves contracting a test solution containing the sample, an antibody for the analyte, and a conjugate of the analyte and a label with a contact portion of a strip of bibulous material capable of being traversed by the test solution through capillary action. The strip contains a first receptor capable of binding to the conjugate. The first receptor is non-diffusively bound to a situs on the strip separate from the contact portion of the strip. The strip further contains a second receptor capable of binding the antibody to the analyte between the situs and the contact portion. The second receptor is non-diffusively bound to the strip. At least a portion of the test solution is allowed to traverse the strip by capillary action and thereby contact the situs.

Abstract: A method is disclosed for separating a substance from a liquid medium. The method comprises combining the liquid medium containing the substance with magnetic particles under conditions for non-specific chemical binding of the magnetic particles. Thereafter, the medium is subjected to a magnetic field gradient to separate the particles from the medium. The preferred non-specific binding is achieved as the result of charge interactions between the particles usually by means of a polyionic reagent. The method of the invention has particular application to the separation of cells and microorganisms from aqueous suspensions and also to the determination of an analyte in a sample suspected of containing the analyte. The analyte is a member of a specific binding pair (sbp). The sample is combined in an assay medium with magnetic particles and a sbp member complementary to the analyte.

Abstract: An apparatus is disclosed for maintaining a biological sample on a support. The apparatus has a hollow chamber with internal and external surfaces and first and second ends. The first and second ends have first and second releasable closures. The apparatus maintains the support in contact with a liquid medium at all times regardless of the orientation of the apparatus. The apparatus is useful for isolating and culturing microorganisms.

Abstract: A method for determining the presence of a specific binding member bound to first particles in a liquid medium is disclosed. The method comprises providing in combination (1) a liquid medium suspected of containing a specific binding member bound to first particles, (2) means for agglutinating the first particles in relation to the presence of the specific binding member, and (3) second particles having the same or a different specific binding member for said means for agglutinating bound thereto, thereby providing for said means to agglutinate the second particles. Agglutination of the first and second particles are separately detectible and distinguishable by spectroscopic measurement. The medium is incubated and agglutination of each of the particles is determined spectroscopically without separating the first and second particles.

Abstract: Methods are disclosed 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: Novel compounds and assay methods are provided for determining the presence of lithium in serum, plasma, urine or other sample without deproteinization. The novel compounds are water soluble derivatives of TWC-crownformazans and provide signal enhancement by increased absorbance of the dye-lithium complex over the dye anion.

Abstract: Squaraine dyes and compositions of matter containing such dyes are disclosed. The squaraine dyes have an absorption maximum greater than 600 nanometers and are particularly useful in conjunction with a helium/neon (He/Ne) laser. Some of the squaraine dyes are hydrophilic and are therefore water soluble or water compatible and others of the squaraine dyes are lipophilic.

Abstract: A method is disclosed for conducting an assay for an analyte. The method comprises causing a specific binding pair member in a first aqueous medium to become bound to a first bibulous member by contacting a portion of the first bibulous member with the medium. The first bibulous member is in liquid receiving relationship with an absorbent member. The contacting is carried out under conditions wherein the first medium traverses the first bibulous member and at least a portion of the absorbent member by capillary action. The method further comprises causing the first bibulous member to come into liquid receiving relationship with a second bibulous member. A reagent in a second aqueous medium is absorbed by and preferably becomes a non-diffusively bound to the second bibulous member in relation to the presence of analyte in the first medium.

Abstract: A method for determining the presence of a predetermined minimum detectible amount of one or more analytes in a sample suspected of containing the analyte is disclosed. Each analyte is a member of a specific binding pair ("sbp member") consisting of ligand and its complementary receptor. The method comprises contacting with a test solution containing the sample and predetermined amounts of two or more of a plurality of first sbp members, each respectively analogous to one of the analytes, a contact portion of a piece of bibulous material capable of being traversed in at least one direction by the test solution by capillary migration. The bibulous material contains predetermined amounts of two or more of a plurality of second sbp members, each respectively capable of binding one of the analytes and corresponding first sbp member.

Abstract: The present invention describes a class of dyes for use in staining cell samples and methods of making such dyes. A preferred class of dyes known as detergent dyes which possess the ability to stain cells in whole blood and are only slowly leached or lost from the stained cells over time are described. The present invention has application, for example, to blood typing for the determination of the presence of blood group antigens A, B, AB, O, and D (Rh.sub.o) and antibodies to such antigens.

Abstract: A chromatographic device is disclosed. The device comprises in combination a housing, a strip of bibulous material non-removably confined in the housing. The strip has a length and width only slightly less than the length and width of the inner walls of the housing. The inner walls of the housing have means attached thereto for supportively confining the strip in the housing. The strip is confined so that (1) the front and back of the strip are essentially free from contact with the walls of the housing and (2) the capillary action of the strip remains substantially unchanged, and (3), where the strip is paper, the strip is allowed to expand as it is traversed by the liquid medium. The bottom end of the housing contains means for enabling contact of a portion of the strip with the liquid medium. The housing further contains means for visually observing the strip and can also contain indicating means cooperative therewith to assist in determining the result of a chromatographic test.

Abstract: A method is disclosed for producing multiple copies of a primary polynucleotide sequence located at the 3' terminus of a polynucleotide. The method comprises (a) forming in the presence of nucleoside triphosphates and template-dependent polynucleotide polymerase an extension of a primary polynucleotide sequence hybridized with a template sequence of a single stranded pattern polynucleotide comprising two or more template sequences each containing one or more site specific cleavage sequences, (b) cleaving into fragments said extension at cleavable polynucleotide sequences in the presence of means for specifically cleaving said cleavable polynucleotide sequences when said extension is hybridized with said site specific cleavage sequences, (c) dissociating said fragments, (d) hybridizing said fragments with single stranded pattern polynucleotide, and repeating steps (a)-(d). Steps (a)-(d) may be conducted simultaneously or wholly or partially sequentially.