The Finecare cTn I Rapid Quantitative Test is a fluorescence immunoassay designed to quantitatively measure cardiac troponin I (cTn I) in human whole blood, serum, or plasma, primarily used as an aid in the diagnosis of myocardial infarction (heart attack). To assist in the diagnosis of myocardial infarction by measuring the concentration of cardiac troponin I, a protein released into the bloodstream when heart muscle is damaged.