Quantitative assay with extended dynamic range

An efficient design for an expanded dynamic range in a lateral flow one step assay for the detection of an analyte in a biological sample is disclosed. The device comprises a multiple strip design, each constructed of four zones; a sample receiving zone, a sample treatment zone, a labeling zone, and a capture zone. The sample containing analyte is accepted in the sample receiving zone in the form of blood, serum, plasma, or urine. It is then carried into the sample treatment zone where it is rendered compatible with the chemistries of the assay strip. The treated sample then flows into the labeling zone where it interacts with visible particles that are coupled to analyte specific binding proteins. The flow continues, carrying the labeled analyte into the capture zone where it is immobilized in specific regions with analyte specific binding proteins. Excess flow is absorbed in an absorbent zone that is in contact with the capture zone. A positive result is interpreted by detection of the visible particles in the specified regions of the capture zone.