Troponin I Rapid Test Card is an immunochromatography based one step in vitro test. It is designed for qualitative determination of cardiac Troponin I (cTnI) in human serum or plasma specimens as an aid in the diagnosis of myocardial infarction.
 
Cardiac troponin I (cTnI) is a cardiac muscle protein with a molecular weight of 22.5 kilodaltons. Together with troponin T (TnT) and troponin C (TnC), TnI forms a troponin complex in heart to play a fundamental role in the transmission of intracellular calcium signal acting-myosin interaction. The human cTnI has an additional amino acid residues on its N-terminal that are not exist on the skeletal forms thus making cTnI a specific marker for indicating cardiac infarction. CTnI is released rapidly into blood after the onset of acute myocardial infarction (AMI). Its release pattern is similar to CK-MB (4-6 hours after the onset of AMI). However, CK-MB level returns to normal after 36-48 hours, while levels of cTnI remains elevated for up to 6-10 days. The level of cTnI is very low in normal healthy people, and not detected in patients with skeletal muscle injury. Therefore, cTnI is a specific marker for diagnosis of AMI.
 
Troponin I Rapid Test Card is a sandwich immunoassay. When serum sample is added to sample pad, it moves through the conjugate pad and mobilizes gold anti-cTnI conjugate that are coated on the conjugate pads. The mixture moves along the membrane by capillary action and reacts with anti-cTnI antibody that is coated on the test region of troponin I test strip.
 
If Troponin I is present at 0.3ng/ml or greater, the result is the formation of a colored band in the test region.  If there is no cTnI in the sample, the area will remain colorless. The sample continues to move to the control area and forms a pink to purple color, indicating the test is working and the result is valid.