DNA origami frame filled with two types of single-stranded tiles

DNA origami and DNA single-stranded tiles (SSTs) are two basic motifs that are widely used in fabricating DNA nanostructures. Typically, DNA origami is self-folded via a long single phage strand (scaffold strand) and this process is aided by a myriad of short oligonucleotides (staple strand). Unlike DNA origami, SSTs construct nanostructures using many unique strands connected with each other to obtain specific shapes. These motifs are material- and labour-consuming, and require multiple different synthetic oligonucleotides, and DNA SSTs tend to remain kinetically trapped in the form of tubes. In this study, we present a new strategy that combines DNA origami with DNA SSTs to construct a DNA nanostructure with a predesigned shape. A rectangular DNA origami frame with ten dozen helper strands was filled with two types of SSTs assembled repeatedly, which avoided the kinetic trap and used fewer synthetic oligonucleotides. The assembly results were identified using atomic force microscopy. The experimental analysis demonstrated the stability and feasibility of the strategy.