Molecular Biophysics Group, Peter Debye Institute for Soft Matter Physics, Universität Leipzig, 04103, Leipzig, Germany.
Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062, Dresden, Germany.
Small. 2021 Apr;17(17):e2007218. doi: 10.1002/smll.202007218. Epub 2021 Mar 16.
Higher-order superstructures of individual DNA origami building blocks are frequently used in DNA nanotechnology in order to increase the structure dimensions and complexity. Here, a purification method is presented to specifically enrich a fully assembled superstructure out of an excess of substructures. The approach is based on pull-down reactions with magnetic beads, where superstructures are captured via an anchor strand on a specific terminus and then become separated from terminus-free structures. By carrying out several pull-down reactions sequentially on different termini, the full superstructures that possess all termini become finally enriched. The approach is demonstrated by purifying linear origami superstructures with up to nine monomers by two-sided pull-down reactions and a T-shaped superstructure in a three-sided pull-down reaction. In all cases, high recovery yields and purities are obtained. A crucial prerequisite for the sequential pull-down scheme is the establishment of highly specific, orthogonal sequence sets for capture, and anchor strands. It is expected that the introduced approach provides a useful and universal method to purify complex DNA origami superstructures with high specificity and yield and this way allows the massive parallel fabrication of nanostructures at high homogeneity.
为了增加结构的尺寸和复杂度，个体 DNA 折纸建筑模块的高阶超结构经常被用于 DNA 纳米技术。这里，我们提出了一种纯化方法，可特异性地从亚结构过剩中富集完全组装的超结构。该方法基于带有磁珠的下拉反应，其中超结构通过特定末端的锚链被捕获，然后与无末端结构分离。通过在不同末端上连续进行几次下拉反应，最终可富集具有所有末端的完整超结构。我们通过双边下拉反应纯化了多达 9 个单体的线性折纸超结构，并通过三边下拉反应纯化了 T 型超结构，证明了该方法的有效性。在所有情况下，均获得了高回收率和高纯度。用于顺序下拉方案的关键前提条件是建立高度特异性的、正交的捕获和锚链序列集。我们期望所提出的方法提供了一种有用的、通用的方法来纯化具有高特异性和高产量的复杂 DNA 折纸超结构，从而可以在高均一性的情况下大规模并行制造纳米结构。
