The current FDA-approved timing for plerixafor is approximately 11 hours prior to apheresis. This is a logistical problem, since plerixafor should be administered by a health care provider, given the risk of hypotension with administration. The primary purpose of this study is, in autologous donors with non-Hodgkins lymphoma and multiple myeloma undergoing hematopoietic progenitor cell mobilization with plerixafor and G-CSF, to determine whether the dosing interval can be increased to 16 hours prior to apheresis. Patients will be admitted to a special clinical research center on the 4th day of G-CSF administration, where the peripheral blood CD34+ count will be measured every 2 hours after plerixafor administration at 5 pm until 9 AM the following day, at which time apheresis will commence. The hypothesis is that plerixafor administration 16 hours prior to apheresis is as safe and effective as plerixafor administration at 11 hours prior to apheresis.