Although for many purposes, low concentrations of DNA
origami are
sufficient, certain applications such as cryo electron microscopy,
measurements involving small-angle X-ray scattering, orin
vivoapplications require high DNA origami concentrations
of >200 nM. This is achievable by ultrafiltration or polyethylene
glycol precipitation but often at the expense of increasing
structural aggregation due to prolonged centrifugation and final redispersion
in low buffer volumes. Here, we show that lyophilization and subsequent
redispersion in low buffer volumes can achieve high concentrations
of DNA origami while drastically reducing aggregation due to initially
very low DNA origami concentrations in low salt buffers. We demonstrate
this for four structurally different types of three-dimensional DNA
origami. All of these structures exhibit different aggregation behaviors
at high concentrations (tip-to-tip stacking, side-to-side binding,
or structural interlocking), which can be drastically reduced by dispersion
in larger volumes of a low salt buffer and subsequent lyophilization.
Finally, we show that this procedure can also be applied to silicified
DNA origami to achieve high concentrations with low aggregation. We
thus find that lyophilization is not only a tool for long-term storage
of biomolecules but also an excellent way for up-concentrating while
maintaining well-dispersed solutions of DNA origami.