Plasminogen is a single chain glycoprotein zymogen and is the precursor of the fibrinolytic enzyme plasmin. Plasminogen deficiencies are classified as hypoplasminogenemia (Type I) or dysplasminogenemia (Type 2) and are associated with decreased extracellular fibrin clearance leading to mucous membrane lesions and ligneous conjunctivitis. The sensitive quantitative measurement of total mouse plasminogen antigen in plasma, serum, or cell culture media samples is easily performed with this 96 well strip format ELISA kit. Plasminogen, plasmin and plasmin antiplasmin complex will be detected by the assay. Plasminogen antigen was found to be 84 ug/ml in a small sample of normal mice. The assay measures total mouse plasminogen in the 2.5-500 ng/ml range. Samples giving mouse plasminogen levels above 500 ng/ml should be diluted in a similar fluid depleted of plasminogen or blocking buffer before use. A 1:1,000-1:10,000 dilution for plasma is suggested for best results. Mouse plasminogen will bind to the capture antibody coated on the microtiter plate. After appropriate washing steps, anti-mouse plasminogen primary antibody binds to the captured protein. Excess primary antibody is washed away and bound antibody is reacted with the secondary antibody conjugated to HRP. Following an additional washing step, TMB substrate is used for color development at 450nm. Color development is proportional to the concentration of plasminogen in the samples. A standard calibration curve is prepared using dilutions of purified plasminogen and is measured along with the test samples. All reagents and standards are provided in these ELISA kits.