Targeting of m(Ch)PrP-res^A568 to late endosomes/lysosomes after infection. SN56 cells with dispersed m(Ch)PrP-res^A568 (left, rows a-d) were incubated with the following markers shown in the middle panels: a, dextran-Alexa Fluor 488 (D) for fluid-phase endocytosis (consistent with results of 22 cells from 2 independent experiments); b, LysoTracker Green DND-26 (LT) for acidic organelles and lysosomes (67 cells from 4 experiments); c, transferrin-Alexa 488 (Tfn) for early/sorting and recycling endosomes (84 cells from 8 experiments); d, cholera toxin subunit B-Alexa 488 (CTx) for raft membranes (52 cells from 6 experiments). The right panels in a-d show merged images of the left and middle panels with m(Ch)PrP-res^A568 in red and the markers shown in green. Arrows indicate some of the colocalizing vesicles (yellow fluorescence), which were observed with dextran (a) and LysoTracker (b) but not with transferrin (c) or cholera toxin (d). a1-d1 show magnified regions of the merged images of a-d, respectively. Scale bars, 20 μm.