The cardiac myocyte is the most physically energetic cell in the body. Its contraction is myogenic, i.e. it is independent of nervous stimulation. All cardiac myocytes are capable of spontaneous rhythmic depolarization and repolarization of their membrane. Cardiac myocytes occupy as much as 75% of cardiac mass but constitute only about one third of the total cell number in the heart. They are highly specialized high-oxygen-content cells and house a large number of mitochondria. Differentiated cardiac myocytes have little capacity to proliferate and show the hypertrophic growth in response to alpha1-adrenergic stimuli via the Ras/MEK pathway. Cardiac myocyte hypertrophy and apoptosis have been implicated in the loss of contractile function during heart failure. Cardiac myocytes have a complex network of signals that regulates their essential role in the rhythmic pumping of the heart. This network is an appealing model system in which to study the basic principles of cellular signaling mechanisms leading to cardiac myocyte death. HCMa from AcceGen Biotech Research Laboratories are isolated from human heart tissue. HCMa are cryopreserved immediately after purification and delivered frozen. Each vial contains >5 x 10^5 cells in 1 ml volume. HCMa are characterized by immunofluorescent method with antibodies to myosin. HCMa are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HCMa are guaranteed to further culture at the conditions provided by AcceGen Biotech Research Laboratories.