FIG. 1.

A method to distinguish differentiation from fusion in coculture system. DiI-labeled bone marrow–derived multipotent stem cells (BMSCs) and carboxyfluorescein diacetate succinimidyl ester (CFDA-SE)-labeled neonatal rat cardiomyocytes (CFDA-SE-NRCM) are cocultured under direct contact and stained with cardiac troponin I (cTnI) to identify cardiomyocytes. Cells double-positive for DiI and cTnI are regarded to differentiate into cardiomyocytes without fusion, and those triple-positive for DiI, cTnI, and CFDA-SE are fused BMSCs with cardiomyocytes. D, differentiation; F, fusion. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article at www.liebertonline.com/ars).