Human Fibronectin ELISA (Enzyme-Linked Immunosorbent Assay) kit employs a quantitative competitive enzyme immunoassay technique that measures human plasma, serum and cell culture supernatant FN in less than 3 hours. A murine antibody specific for FN has been pre-coated onto a 96-well microplate with removable strips. FN in standards and samples is competed by a biotinylated FN sandwiched by the immobilized antibody and streptavidin-peroxidase conjugate. All unbound material is then washed away and a peroxidase enzyme substrate is added.