Phase One: Four Different types of stem cells will be tested ( Freshly aspirated Bone marrow cells, cryopreserved cells, umbilical cord cells, Stem cells mobilised from bone marrow by g-csf, mesenchymal cells), and the efficacy of labelling documented and effect on viability noted. 3 samples of each type will be tested and the results will be documented. Different cells are being tried to test the efficiency of the labelling technique in different types of cells. This will provide the protocols for all future labelling studies. This will be conducted in collaboration between the stem cell department, nuclear medicine department and nuclear cardiology department.