This test card is used for quantitative determination of myoglobin in human serum, plasma or whole blood in vitro. Myoglobin is a kind of protein existing in the cytoplasm of myocardium and skeletal muscle. It transports oxygen to muscle cells and can also serve as an oxygen storage capsule. The molecular weight of myoglobin is 17.8kd, so it can enter the blood circulation rapidly after myocytes are damaged. The determination of serum myoglobin is one of the indexes for the diagnosis of acute myocardial infarction (AMI), reinfarction and successful reinfusion after thrombolysis. The concentration of myoglobin increased about two hours after the symptoms appeared, so it can be used as an early indicator for the diagnosis of myocardial infarction. According to different measures of reinjection, the concentration of myoglobin in the blood circulation can reach the peak 4 to 12 hours after the onset of infarction, and then it will drop to the normal level about 24 hours later. Myoglobin concentration can also be increased after skeletal muscle damage and severe renal dysfunction.