Analysis of C4F6 binding by SOD1 variants encoding mutations at Lys residues.

CHO cells were transfected with plasmids for each SOD1:YFP variant and after 48 hours the cells were fixed and immunostained as described in Methods. One image of direct YFP fluorescence was captured before a second image of C4F6 immunoreactivity (red) was captured, using a conventional epifluoresence microscope (20x magnification). Cells transfected with WT-SOD1:YFP serve as a negative control and cells transfected with G93A-SOD1:YFP serve as a positive control. Each transfection was repeated at least 3 times and at least 3 fields of view were counted for cells expressing the YFP fusion protein that were also labeled with C4F6 (Table 1).