Immunofluorescent microscopy for the identification of human necrotic myocardium.

Human postmortem cardiac muscle was studied by immunofluorescent microscopy. Necrotic cells in acute myocardial infarctions were first identified with the hematoxylin-eosin stain as showing hypereosinophilia and autofluorescence. The results of the immunofluorescence staining showed a marked decrease if not absence of labeling for the Ca+ and Mg+ adenosine triphosphatase (ATPase) and tropomyosin in all necrotic muscle cells within a myocardial infarction. Myocytolytic cells located at the border of the infarct showed a labeling intensity similar to that of normal muscle cells. The use of immunofluorescence localization of muscle-specific proteins can be used as a reliable method to detect myocardial cell necrosis.