Blood stem cells will be collected when your blood counts have returned to normal (about 10-16 days after the chemotherapy). The process of stem cell collection takes about 4 hours. It may take 1-6 sessions to collect the number of stem cells needed for the transplant. The process of stem cell collection is called apheresis. A machine is attached to the catheter under the collar bone and blood is withdrawn. The blood then flows through the machine, which removes stem cells from the blood. The blood is then returned back to you through the catheter. The stem cells are then frozen and stored. These stem cells will be given back to you after the next phase of treatment to help your blood counts recover after high dose chemotherapy. After enough stem cells have been collected, you will be admitted to the hospital for high dose chemotherapy.