Nongenetic method for purifying stem cell-derived cardiomyocytes

Several applications of pluripotent stem cell (PSC)-derlved cardlomyocytes require elimination of undifferentiated cells. A major limitation for cardlomyocyte purification Is the lack of easy and specific cell marking techniques. We found that a fluorescent dye that labels mitochondria, tetramethylrhodamlne methyl ester Perchlorate, could be used to selectively mark embryonic and neonatal rat cardlomyocytes, as well as mouse, marmoset and human PSC-derlved cardlomyocytes, and that the cells could subsequently be enriched (>99% purity) by fluorescence-activated cell sorting. Purified cardlomyocytes transplanted Into testes did not Induce teratoma formation. Moreover, aggregate formation of PSC-derlved cardlomyocytes through homophlllc cell-cell adhesion Improved their survival In the lmmunodefident mouse heart. Our approaches will aid In the future success of using PSC-derlved cardlomyocytes for basic and clinical applications.