ab118170 ligand binding and displacement. Top (a, C): ab118170 binding to two different live cell lines expressing β1 (A) or β2 (C) adrenoceptors. Bottom (B, D): Binding blocked in the same two cell lines β1 (B) or β2 (D) by the unlabelled competitor ICI118551 (1 µM). Nuclei have been counter-stained with Hoechst.