This test card is used for quantitative determination of CK-MB in human serum, plasma or whole blood in vitro. Creatine kinase (CK) is a dimer enzyme with four different forms: mitochondrial isoenzyme and cytosolic isoenzyme CK-MM (muscle type), CK-BB (brain type) and CK-MB. Serum CK-MB is an important index for the diagnosis of myocardial ischemia (such as acute myocardial infarction, myocarditis, etc.). CK-MB can be detected 3-8 hours after the occurrence of cardiac symptoms and can last for a long time, depending on the course of the disease. CK-MB can also occur in other clinical conditions, such as rhabdomyolysis and stroke. In laboratory diagnosis, the determination of total CK, troponin T and / or myoglobin is helpful to distinguish these clinical diseases.