4.1. Origami Purification

DNA origami nanostructures were synthesized as described previously [11] and subsequently PEG purified. Folded DNA origami structures were mixed 1:1 (v/v) with 2× PEG purification buffer (PEG-8000 15% (w/v), 500 mM NaCl, 1× TE buffer), centrifuged for 30 min at 17,900 rcf and 4 °C. The supernatant was removed and the DNA origami resuspended in folding buffer (12.5 mM MgCl₂, 10 mM Tris, 1 mM EDTA at pH 8.0) by shaking and heating for 5 min at 600 rpm and 30 °C. Previously described steps were repeated two times to increase the purification. Finally, DNA origami nanostructures were stored at −20 °C until use. The assembly of DNA origami nanostructures was confirmed using DNA-PAINT microscopy (Figure 2 and Figure A3). Origami structures exposed the docking sequence 5′-TTATACATCTA-3′, consisting of a TT-spacer followed by nine nucleotides complementary to the imager sequence.