BACKGROUND:The success of cell therapy will depend on the ability to monitor the fate of transplanted cells in vivo.Superparamagnetic iron oxide(SPIO)labeling is an ideal magnetic resonance contrast medium,and it offers the potential for non-invasive tracking of implanted cells.The chlormethylbenzamido-1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (CM-Dil)labeling does not have cytotoxicity,so it cannot influence cell growth.OBJECTIVE:To investigate the effects of SPIO and CM-Dil labeling and tracking on bone marrow mesenchymal stem cells(BMSCs).METHODS:Porcine BMSCs were isolated and cultured by the whole bone marrow method.BMSCs were labeled with SPIO containing 50 mg/L Ferrum and CM-Dil.The labeled BMSCs were transplanted into porcine myocardial infarction model via intracoronary infusion.The frozen sections of the cardiac tissues were obtained after 4 weeks.RESULTS AND CONCLUSION:Efficiency of SPIO and CM-Dil labeling BMSCs was nearly 100%.The SPIO and CM-Dil labeled BMSCs could be found in the cardiac muscle tissues at 4 weeks after transplantation.SPIO and CM-Dil labeling BMSCs were efficiently tracked in vivo.