If you are going to have leukapheresis, you may visit the Apheresis Clinic at MD Anderson. For the leukapheresis procedure, you will need to stay seated in a chair and keep both arms still for about 3 hours. Blood will be drawn from 1 arm, white blood cells will be separated from the rest of the blood cells in the leukapheresis machine, and the red cells, platelets, and plasma (liquid part of the blood) will be returned through your other arm. The leukapheresis procedure may require a total of 4-6 hours each day for up to 2 days.