US27 surface levels remain constant over time.

<p>3T3-CXCR4/US27 cells were treated with 100 ng/ml CXCL12 or PBS for the indicated times, harvested, and then labeled with membrane impermeable fluorogen and analyzed via flow cytometry. (A) αRED fluorescence labeling of surface US27. (B) Fluorescence intensity pre-treatment was set as 100% and intensity at each time point expressed as % initial level. (C) αRED labeling of surface CXCR4 and (D) percent total initial surface levels calculated as above. Error bars represent standard error among three independent replicate experiments.