Cardiac progenitor cells are derived from the heart (of a single donor) that has been dissociated into single cells and cultured using differential adhesion. These cells are characterized by immunostaining of desmin and other cardiac developmental markers, and enable researchers to produce highly purified cardiomyocytes and their progenitors. Cardiac progenitor cells may be used in various in vitro, or in vivo studies; transplantation into normal or diseased systems; cardiac toxicology studies; or cardiovascular developmental studies.