Figure 3.

Analysis of triple helix formation by a comigration assay. The labeled 89-mer oligonucleotide was incubated in 50 mM Tris⋅HCl, pH 7.5/10 mM MgCl₂/10 mM DTT/1 mM ATP/25 μg/ml BSA, in the absence of any plasmid (lane 1) or in the presence of 60 fmol of supercoiled pAR1 (lane 2), 60 fmol of pAR1 digested by BamHI and XhoI (lane 3), or 60 fmol of pAR4 (lane 4). Samples were loaded on a 6% polyacrylamide gel and migrated at 37°C in TBE buffer containing 10 mM MgCl₂.