Fig. 1. Effects of permeabilization on clathrin-coated pits. (A-D) Clathrin-coated pits were fixed before (a,b) and after (c,d) permeabilization. Cells were imaged for both GFP (a,c) or Alexa 546 (b,d) fluorescence. Immunostained cells were imaged for clathrin in (A, b,d), for AP2 (B, b,d), and for epsin (C, b,d). In D, cells were loaded with Alexa 546 transferrin and imaged for transferrin (b,d). Notice that, all fluorescence settings used in comparing nonpermeabilized and permeabilized cells were identical. Bars, 10 µm.