<p><b>a,b.</b> Z-stack overlay of a typical tCXCR4/CatCh cell either treated with 50 nM SDF1α for 45 min (a) or with AMD3100 (b). The tandem construct is internalized by the action of SDF1α (similar to CXCR4 shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0165344#pone.0165344.g002" target="_blank">Fig 2</a>). <b>c.</b> Internalization of anti-CXCR4 antibody after immunoreaction with tCXCR4/CatCh in cells exposed to 50 nM SDF1α. The fluorescence signal of anti-CXCR4 (top, red) and tCXCR4/CatCh (middle, cyan) co-localize to a great extend as can be seen from white areas in the overlay (bottom). Scale bars represent 10 μm.</p
