Fig. 1. CD81 and CD9 are abundantly expressed at the apical, phagocytic surface of RPE cells. (A,B) Polarized live RPE-J cells on ice were labeled with CD81 or CD9 antibodies as indicated and shown in green, subsequently fixed and labeled with ZO-1 tight junction protein antibody (red). Nuclei are shown in blue in the merged fields. Maximal projections of representative whole cell x-y scans acquired at 0.2 µm intervals are shown. (C-H) Representative confocal x-z scans of polarized RPE-J cells co-labeled with antibodies to CD81, CD9, ZO-1, 1 integrin, P-cadherin or v5 receptors as indicated. CD81, CD9 and v5 were labeled in live cells on ice as in (A,B). ZO-1, 1 integrin and P-cadherin were labeled after fixation and permeabilization. Single and merged channels of the same field are shown with the labeled proteins indicated above each single channel picture. Bars, 10 µm.