Why do some stem cell facilities around the world require days to weeks before removal of mesenchymal stem cells until reinsertion into the patient?

These facilities are obtaining stem cells from bone marrow or blood in relatively small quantities and they are then culturing (growing) the cells to create adequate quantities. Research seems to indicate that the success of treatment is directly related to the number of cells injected. Sparrow uses adipose-derived stem cells that are abundant naturally at approximately 2,500 times levels found in bone marrow (the most common source of mesenchymal stem cells). Sparrow uses technology that isolates adipose stem cells in vast numbers in a short time span so that prolonged culturing is unnecessary and cells can be deployed into a patient within 90 minutes of harvesting.