Granulocyte colony-stimulating factor (G-CSF) will be administered to suitable patients to mobilise their haematopoietic stem cells (HSCs) from the bone marrow into the peripheral circulation. These blood cells will be collected from each patient by leukapheresis. CD34 positive stem cells will then be isolated by immunoselection and introduced into a Nunc cell factory where the subset of CD34 positive stem cells will be allowed to attach to the plastic trays within the cell factory for 2 hours at 37 degrees C in 5 percent carbon dioxide. After this period the non-attached CD34 positive cells will be washed from the system and the progeny of the attached cells secreted into the supernatant media expanded in the presence of growth medium supplemented with growth factors. At the end of 6 days expansion, the stem cells will be differentiated into insulin and c-peptide protein excreting cells over the next 14 days by the addition of specified reagents/growth factors and continued incubation at 37 degrees C in 5 percent carbon dioxide in accordance with the principles of Good Manufacturing Practice. As an optional step the cells can be labelled with iron oxide to allow tracking of the cells by Magnetic Resonance Imaging (MRI) scan, before being infused into the patient.