... this isomer is non-existent, making a cardiac - specific troponin I.Acute myocardial damage, cTnI immediate access to blood circulation, a ... is only used in vitro measurement of serum cardiac troponin I (cTnI). Reaction devices and processing specimens in accordance with ... , in order to avoid a false positive result, the need fresh blood sample within three hours of use. Needless to temporarily take ...