Light micrograph of myocardium (heart muscle). The cardiomyocytes (heart muscle cells) form interconnecting strands with one another. Fine striations (thin lines) are present in the eosinophilic (pink) cytoplasm. Intercalated disks are seen as shorter lines perpendicular to the striations. The cardiomyocyte nuclei are seen as the blue-purple elongated structures. Also seen is golden-yellow lipofuscin pigment. Haematoxylin and eosin stained tissue section. Magnification: 400x when printed at 10cm.