Fig. 5. Effects of PrP^C depletion on ROS levels in SN56 cells. (A) Immunofluorescence images of fixed cells that were transfected with either scramble (a,b) or sequence 1 (c,d) oligonucleotides and conjugated to Dye547-3' as an indicator of transfection (a,c) or stained with DFA to show ROS levels (b,d). The asterisks indicate cells not transfected with oligonucleotides. The images were produced using identical scan-settings that allowed direct comparison of fluorescence intensities. Bar, 20 µm. (B) The level of ROS was measured 72 hours after siRNA oligomer transfection in the presence and absence of Htt. ^*P<0.05 and ^**P<0.01 compared with control transfected cells.