Abstract: This invention describes compositions and methods for use in PSA assays having low functional sensitivity which are useful, for example, in the detection of early stage recurrence of prostate disease following treatment and in the determination of whether patients have early stage biochemical reoccurrence (ES-BCR) or stable disease.

Abstract: This invention describes compositions and methods for use in PSA assays having low functional sensitivity which are useful, for example, in the detection of early stage recurrence of prostate disease following treatment and in the determination of whether patients have early stage biochemical reoccurrence (ES-BCR) or stable disease.

Abstract: This invention describes compositions and methods for use in PSA assays having low functional sensitivity which are useful, for example, in the detection of early stage recurrence of prostate disease following treatment and in the determination of whether patients have early stage biochemical reoccurrence (ES-BCR) or stable disease.

Abstract: The present invention is directed to a membrane-based immunoassay method for an analyte of interest having at least two sterically separate antigenic sites. The method comprises providing a reactive membrane having a calibration zone and a test zone, wherein the calibration zone is characterized by having a predetermined amount of the analyte of interest immobilized via a first antibody as a first specific binding pair to a solid phase, the immobilized first binding pair being covalently cross-linked such that any remaining binding sites on said first immobilized antibody are substantially incapable of further specifically binding to any additional analyte, but at least some of said analyte is capable of specifically binding to a preselected amount of a labelled second antibody.