Soluble FMRpolyG-GFP Quantification

For assessment of soluble FMRpolyG-GFP after ASO–CCG treatment, we used COS7 cells, 48-well plate, 100 ng of 100×CGG construct, 100 ng of 100×CGG-mCherry construct, and 50 ng of reference mCherry construct per well and 11-nucleotide-long ASOs at 125 or 200 nM. After 48 h cells were harvested and proceeded according to FL-SDS-PAGE protocol described with details in ref. ^{23 (link)}. Shortly, cells were lysed, vortexed, and sonicated. In total, 10 µl of lysate without previous heat denaturation was electrophoretically separated in 12% polyacrylamide SDS gel. The fluorescence signal was captured directly in the gel with the use of Amersham Typhoon RGB Biomolecular Imager.