The Rat Skeletal Troponin I Kit provides assay-specific components for the quantitative determination of endogenous skeletal troponin I (sTnI) in rat serum and plasma. Troponin is a heterodimer that regulates muscle contraction in skeletal and cardiac muscle. Troponin acts with intracellular calcium to control the interaction of actin and myosin filaments in striated muscle fibers. When muscle tissue is damaged, the troponin-tropomyosin complex breaks down and troponin I and troponin T are released into the blood. cTnT and cTnI can be readily distinguished from their skeletal muscle analogs making them excellent biomarkers for myocardial injury and cardiotoxicity.