Cell assay of inclusion formation by SOD1 variants encoding mutations at lysine residues.

CHO cells were transfected with plasmids for each SOD1:YFP variant and representative pictures of direct YFP fluorescence were taken at 24 and 48 hours post-transfection, using a conventional epifluoresence microscope (20x magnification). G93A-SOD1:YFP provides a positive control for inclusion formation and WT provides a negative control for inclusion formation. The percentage of cells expressing these mutants (K30V, K36T, K75A, or K91G) that developed inclusions was far lower than the positive control G93A variant (Table 1).