Abstract: The efficiency and accuracy of one-step lateral flow assays can be improved by employing more efficient binding between participants in labeling and capture. Thus, in addition to analyte/anti-analyte interactions, specific binding is achieved through members of an irrelevant specific binding pair. Also included within the invention is a format wherein unlabeled competitor for analyte serves as a gatekeeper in the capture zone, competing with analyte for labeled anti-analyte, which analyte will be captured in a detecting portion of a capture zone.

Abstract: One-step enzyme immunoassays in which enzyme-antibody conjugate or label and enzyme substrate are separated until separation of bound and free enzyme conjugate or label is complete. This separation is accomplished by using variable flow paths, immobilization of substrate at the test line, placement of substrate in a sac or association with a particle label, enzyme product chemical capture, delay zone dissolution and protected enzyme substrates.

Abstract: One-step enzyme immunoassays in which enzyme-antibody conjugate or label and enzyme substrate are separated until separation of bound and free enzyme conjugate or label is complete. This separation is accomplished by using variable flow paths, immobilization of substrate at the test line, placement of substrate in a sac or association with a particle label, enzyme product chemical capture, delay zone dissolution and protected enzyme substrates.

Abstract: Methods and devices for distinguishing between normal and abnormal pregnancies are provided. The methods rely on determining the concentration of progesterone or progesterone metabolite in a patient sample, where a concentration above a threshold value is indicative of a normal pregnancy. Preferably, the concentration of hCG is determined simultaneously, where an hCG concentration above a threshold value provides confirmation that the individual being tested is pregnant. An exemplary test device comprises a lateral flow membrane having zones for capturing label in response to the progesterone and hCG concentrations, respectively. Visible label is accumulated when the hCG concentration exceeds the threshold value but is absent when the progesterone concentration exceeds the threshold value.

Abstract: A lateral flow assay device for detecting the presence of Chlamydia antigen in patient's samples comprises a flow matrix including a labelling zone and a capture zone. Labelling complex comprising antibodies specific for an epitope on the lipopolysaccharide antigen of Chlamydia is present within the labelling zone. Immobilized antibody specific for the same or another epitope of the lipopolysaccharide antigen of Chlamydia is located in the capture zone. The sample containing the Chlamydia antigen will flow first through the labelling zone, where it complexes with the labelling complex, and then to the capture zone, where it is captured by the immobilized antibody. Chlamydia antigen may be extracted from a patient sample, such as a endocervical swab, by first extracting the antigen in a strong base followed by neutralization with a zwitterionic detergent and a blocking protein present in a zwitterionic buffer.

Abstract: A particularly efficient design for a nonbibulous lateral flow one step assay for an analyte in a biological sample is disclosed. In the improved device of the invention, three zones which are in nonbibulous lateral flow contact are employed: a sample receiving zone, a labeling zone, and a capture zone. The sample containing analyte is carried through the labeling zone and interacts with an assay label comprising visible moieties, preferably particles, which are coupled to specific binding reagent for analyte or to a competitor with analyte for a capture reagent. The flow continues into the capture zone where the visible moieties to which analyte or competitor are coupled are captured. Excess fluid is absorbed into an absorbent zone in contact with the capture zone. A positive result is obtained by visualizing the visible moieties in the capture zone.

Abstract: A particularly efficient design for a nonbibulous lateral flow one step assay for an analyte in a biological sample is disclosed. In the improved device of the invention, three zones which are in nonbibulous lateral flow contact are employed: a sample receiving zone, a labeling zone, and a capture zone. The sample containing analyte is carried through the labeling zone and interacts with an assay label comprising visible moieties, preferably particles, which are coupled to specific binding reagent for analyte or to a competitor with analyte for a capture reagent. The flow continues into the capture zone where the visible moieties to which analyte or competitor are coupled are captured. Excess fluid is absorbed into an absorbent zone in contact with the capture zone. A positive result is obtained by visualizing the visible moieties in the capture zone.

Abstract: The present invention provides specific binding solid phase assay methods and kits for the detection of the presence or absence of a microorganism by directly staining the microorganism and specifically capturing the stained microorganism on a solid support. The methods find particular utility in the detection of Candida. The methods may simultaneously detect the presence or absence of multiple microorganisms.

Abstract: A "one step" device for the detection of analytein clinical assays is disclosed. A visible label comprising a visible moiety and a ligand that binds to or competes with analyte is contained in a fluid conducting membrane or prefilter; and the analyte and associated ligand are conducted by the flow of sample into a detection zone. The detection zone contains a capture reagent that binds to label or to analyte bound to label.

Abstract: Polysaccharide antigens characteristic of Group A or B Streptococci are extracted for use in immunodiagnostic assays by a simplified method. The method involves the use of two dried reagents, sodium nitrite and Tris base, and a liquid reagent, acetic acid.

Abstract: The present invention relates generally to test articles and assays for the detection of analytes in biological fluid samples. More particularly, the present invention relates to test articles an assays which employ dyed microorganisms as visual labels to detect suspected analytes.

Abstract: The present invention provides devices, methods, and kits for treatment and detection of analytes requiring pretreatment in samples. One-step treatment and detection is possible utilizing the devices and methods of the present invention.

Abstract: A wash solution having a pH of from about 7 to about 12 comprises at least about 0.1 weight percent of one or more cationic surfactants. This wash solution is useful in assays for chlamydial or gonococcal organisms, such as Chlamydia trachomatis or Neisseria gonorrhoeae. In particular, it can be used to remove uncomplexed materials from the insolubilized complexes formed between antigen and antibodies.

Abstract: An extraction composition is useful for lysing chlamydial, gonococcal or herpes organisms and extracting detectable antigen from the organisms. In particular, this composition has a high pH (at least about 8) and comprises an alcoholamine which is effective in extracting antigen. It is particularly useful for extracting either or both of the lipopolysaccharide and major outer membrane protein chlamydial antigens.

Abstract: Antigens extracted from chlamydial or gonococcal organism are rapidly and ionically bound directly to a polymeric solid support which has cationic groups on its surface. The support is substantially free of any antibody or other biological compound reactive with the antigen. Ionically bound antigen is then contacted with suitable chlamydial or gonococcal antibodies to form a bound immunological complex which is detected in suitable fashion, for example by using a labeled anti-body. The entire assay, carried out at room temperature, requires less than 30 minutes and is highly sensitive.

Abstract: A wash solution having a pH of from about 7 to about 12 comprises at least about 0.1 weight percent of one or more cationic surfactants. This wash solution is useful in assays for chlamydial or gonococcal organisms, such as Chlamydia trachomatis or Neisseria gonorrhoeae. In particular, it can be used to remove uncomplexed materials from the insolubilized complexes formed between antigen and antibodies.

Abstract: An immunological reagent composition is useful for the determination of chlamydial or gonococcal antigens extracted from the respective organisms in a biological specimen. It is particularly useful for the determination of Chlamydia trachomatis or Neisseria gonorrhoeae. The composition comprises an antibody to a chlamydial or gonococcal antigen or an anti-antibody, a nonimmunological blocking protein having a pI from about 4 to about 7, and an amphoteric surfactant present in an amount of at least about 0.001 weight percent.