Figure 2.

A. Transmission electron micrograph of typical normal mitochondria in a cardiomyocyte (scale bar – 1.0μm). B. Irreversible cellular membrane damage (cytoplasmic membrane invaginations as indicated by black arrows) and disruption of myofibrils in a cardiomyocyte after straight freezing in liquid nitrogen under normal pressure (scale bar – 1.0μm). C. Decreased density of the mitochondrial matrix in a cardiomyocyte after incubation at high-pressure nitrogen-oxygen gas mixture and cooling in liquid nitrogen (scale bar – 2.0μm). D. Preserved mitochondria in a cardiomyocyte after applied cryostasis (incubation in high-pressure xenon-oxygen mixture followed by cooling in liquid nitrogen) (scale bar – 1.0μm).