Abstract: The present invention provides analytical devices comprising primary and secondary flow paths. A secondary flow path is configured to allow for a portion of a liquid sample to enter the secondary flow path from a primary flow path and subsequently be drawn back into the primary flow path, thereby providing sequential delivery of a portion of the sample to downstream locations.

Abstract: Compositions and processes for qualitative or quantitative one-step, two-site, tag/anti-tag or competitive non-bibulous lateral flow (immunochromatographic) assays for analytes in body fluids including chemically modified proteins as blocking and/or dispersing agents in conjunction with additives eliminating non-specific interference with the detection agents and/or binding partner caused by endogenous polypeptide constituents. Composition of the chemically modified proteins can be albumins. Composition of the chemically modified albumins can have altered charge and/or molecular weight. Process for composition of the chemically modified proteins can be prepared by modification of the nucleophilic groups. The chemical modification of nucleophilic groups in albmins can be introduced by anhydrides, alkyl acetimidates, methylating and/or cross-linking agents. The additives eliminating non-specific interference can be chemically modified albumins, heterophilic blockers and chaotropic agents.

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.