Alpha-2-antiplasmin is the major circulating inhibitor of plasmin. It plays a role in the regulation of intravascular fibrinolysis. Decreased levels of alpha-2-antiplasmin may play an important role in the increased capacity of the fibrinolytic function and may be beneficial in the treatment of thrombotic diseases, acute pulmonary embolism, and hepatic repair. The sensitive quantitative measurement of total mouse alpha-2-antiplasmin antigen in plasma or serum samples is easily performed with this 96 well strip format ELISA kit. The normal mouse concentration of antiplasmin is 86 ug/ml in plasma. The assay measures total antiplasmin in the 0.1-100 ng/ml range. Samples giving mouse antiplasmin levels above 100 ng/ml should be diluted in blocking buffer before use. A 1:10,000-20,000 dilution for plasma is suggested for best results. Mouse antiplasmin will bind to the capture antibody coated onto a micro titer plate. Free and complexed antiplasmin will bind to the plate and will be detected by the assay. After appropriate washing steps, biotin labeled anti-mouse antiplasmin primary antibody binds to the antiplasmin. Excess antibody is washed away, and bound antibody is reacted with peroxidase conjugated streptavidin. Following an additional washing step, TMB substrate is used for color development at 450 nm. Color development is proportional to the concentration of antiplasmin in the samples. A standard calibration curve is prepared using dilutions of purified antiplasmin and is measured along with the test samples. All reagents and standards are provided in these ELISA kits.