Method to identify the proliferative potential of individual endothelial cells (ECs). ECs derived from cord or adult blood EPCs were transduced with a retrovirus-encoding green fluorescence protein, the expressing cells were identified, and single cells were plated using a fluorescence-activated cell sorter equipped with a single-cell deposition device. The green fluorescing cells were visualized through a fluorescence microscope, and the number of cells in each well was directly counted. Microscope, objective, and camera details are as in Figure 1.