Schematic representations of the DNA used in this study. S1 serves as a control and contains no triplet repeat tracts. S1-CGG19 contains 19 CGG/CCG repeats (black) within the S1 flanking sequence (gray). S1-CAG19 contains 19 CAG/CTG repeats (blue) within the S1 flanking sequence (gray). S1-1AGGa, S1-1AGGb, and S1-2AGG contain AGG/CCT interruptions (orange) within the repeat tract. FMR1-CCG19, FMR1-1AGGa, FMR1-1AGGb, and FMR1-2AGG also contain CGG/CCG repeats (black) and AGG/CCT interruptions (orange), however they contain the FMR1 flanking sequence (NG_007529.1, dashed). Please refer to the supporting information for the DNA sequences.