StemExpress offers PBMCs and CD34+ stem cells mobilized with G-CSF, Plerixafor, and G-CSF plus plerixafor. The mechanism of action of these mobilization agents, and the combination of them, have been shown to change the expression profile, cell composition, and engraftment potential of the mobilized cells.1,2,3 Therefore, it is important to understand that switching mobilization reagents during a study may also change the mobilized cell type and their effect on studies relating to transplantation and stem cell research. 1. Broxmeyer, et al. (2005) Rapid mobilization of murine and human hematopoietic stem and progenitor cells with AMD3100, a CXCR4 antagonist. J Exp Med. 201(8):1307–1318. 2. Larochelle, et al. (2006) AMD3100 mobilizes hematopoietic stem cells with long-term repopulating capacity in nonhuman primates. Blood. 107(9):3772–3778. 3. Lidonnici, et al. (2017) Plerixafor and G-CSF combination mobilizes hematopoietic stem and progenitors cells with a distinct transcriptional profile and a reduced in vivo homing capacity compared to plerixafor alone. Haematol. 102(4):120-124.