Guide to Designing DNA Origami Nanostructures Published

Intrigued by DNA origami, but not sure how to use to build structures?

Jacob Majikes and Alex Liddle, researchers at the National Institute of Standards and Technology (NIST) who have studied DNA origami for years, have compiled the first detailed tutorial on the technique. Their comprehensive report provides a step-by-step guide to designing DNA origami nanostructures, using state-of-the-art tools. Their guide was published last week in the Journal of Research of the National Institute of Standards and Technology.

"We wanted to take all the tools that people have developed and put them all in one place, and to explain things that you can't say in a traditional journal article," said Majikes. "Review papers might tell you everything that everyone's done, but they don't tell you how the people did it. "

DNA origami relies on the ability of complementary base pairs of the DNA molecule to bind to each other. The binding enables short strands of DNA to act as "staples," keeping sections of long strands folded or joining separate strands. A typical origami design may require 250 staples. In this way, the DNA can self-assemble into a variety of shapes, forming a nanoscale framework to which an assortment of nanoparticles—many useful in medical treatment, biological research and environmental monitoring—can attach.

The challenges in using DNA origami are twofold, said Majikes. First, researchers are fabricating 3D structures using a foreign language—the base pairs A, G, T and C. In addition, they're using those base-pair staples to twist and untwist the familiar double helix of DNA molecules so that the strands bend into specific shapes. That can be difficult to design and visualize. Majikes and Liddle urge researchers to strengthen their design intuition by building 3D mock-ups, such as sculptures made with bar magnets, before they start fabrication. These models, which can reveal which aspects of the folding process are critical and which ones are less important, should then be "flattened" into 2D to be compatible with computer-aided design tools for DNA origami, which typically use two-dimensional representations.