Uptake of prom1-exo by FEMX-I and MSC. A. Cells were incubated for 3 h with PKH67-labeled green fluorescent prom1-exo, fixed and stained with phycoerythrin-conjugated AC133 anti-prominin-1 antibody. Arrows represent areas of co-localization of green PKH67 fluorescence and red fluorescent anti-prominin-1 antibodies. Since MSC do not express prominin-1, there could be no interference from an endogenous MSC prominin-1 pool. Bars, 25 μm. B. MSC were incubated for 3 h with prom1-exo prepared from FEMX-I cells transiently transfected with a prominin-1-GFP fusion plasmid.