• Blood Priming: Blood priming of the apheresis machine is at the discretion of the institution. • Apheresis Procedure: The apheresis procedure will be performed in accordance with institutional standards. • PBSC Collection Goal: The PBSC c ollection goal is 2 x10 6 CD 34+ cells/kg. • PBSC Product Testing: Each PBSC collection will be cultured for bacterial and fungal contamination, nucleated cell count and differential, and CD34+ cell enumeration. 15.3.5 GUIDELINES FOR SALVAGE CHEMOTHERAPY AND PBSC COLLECTION As no study drug is administered during the salvage chemotherapy phase of the trial and administration of salvage chemotherapy is a standard -of-care for patients not amenable to HDC, the salvage regimen for Group B patients and mobilization and collection of PBSCs may be administered at UF or other Foundation for the Accreditation of Cellular Therapy (FACT) -accredited medical institutions under the care of a board - eligible/board -certified pediatric oncologist, with the exception of the first leukapheresis for collection of PBMCs for DC and xALT generation, which must occur at the main institution. Subsequent PBSC mobilization and leukapheresis may be conducted according to institutional guidelines. PBSC products collected and cryopreserved at FACT -accredited institutions shall be shipped in a dry shipper to the Stem Cell Laboratory under per SOPs prior to NMA conditioning with cyclophosphamide and fludarabine. Dr.