(a) Structure of the mixmer ASOs. F is 2′-F. X is either DNA, RNA, 2′-OMe, 2′-MOE or cEt. For each ASO, every X has the same chemistry. (b) Real-time RT-PCR analysis of SMN2 transcripts including exon 7 following ASO treatment of fibroblasts from patients with SMA. The concentration of transfected ASO is shown above the graph. The data points are the average of duplicate samples. (c) Same as in b, except that the real-time RT-PCR analysis is for SMN2 transcripts excluding exon 7.