Create Fertility Centre 2 articles published in JoVE Developmental Biology The Aortic Ring Co-culture Assay: A Convenient Tool to Assess the Angiogenic Potential of Mesenchymal Stromal Cells In Vitro Farwah Iqbal1,2, Yarden S. Gratch1, Peter Szaraz1,2, Clifford L. Librach1,2,3,4,5 1Create Fertility Centre, 2Department of Physiology, University of Toronto, 3Department of Obstetrics and Gynecology, University of Toronto, 4Department of Medical Sciences, University of Toronto, 5 Here, we present a novel application of the aortic ring assay where prelabelled mesenchymal cells are co-cultured with rat aorta-derived endothelial networks. This novel method allows visualization of Mesenchymal Stromal Cells (MSCs) homing and integration with endothelial networks, quantification of network properties, and evaluation of MSC immunophenotypes and gene expression. Developmental Biology In Vitro Differentiation of Human Mesenchymal Stem Cells into Functional Cardiomyocyte-like Cells Peter Szaraz*1,2, Yarden S. Gratch*1, Farwah Iqbal1,2, Clifford L. Librach1,2,3,4,5 1Create Fertility Centre, 2Department of Physiology, University of Toronto, 3Department of Obstetrics and Gynecology, University of Toronto, 4Department of Physiology, University of Toronto, 5 Here, we present a method to efficiently harness the cardiac differentiation potential of young sources of human mesenchymal stem cells in order to generate functional, contracting, cardiomyocyte-like cells in vitro.