More on DNA building blocks

From Soft machines, discussion about a paper on DNA structures. Rapid Chiral Assembly of Rigid DNA Building Blocks for Molecular Nanofabrication Practical components for three-dimensional molecular nanofabrication must be simple to produce, stereopure, rigid, and adaptable. We report a family of DNA tetrahedra, less than 10 nanometers on a side, that can self-assemble in seconds with near-quantitative yield of one diastereomer. They can be connected by programmable DNA linkers. Their triangulated architecture confers structural stability; by compressing a DNA tetrahedron with an atomic force microscope, we have measured the axial compressibility of DNA and observed the buckling of the double helix under high loads.

The European writers devised a method of making rigid DNA tetrahedra, with edges less than 10 nm in size, at high (95%) yield. They also measured the stiffness of the DNA tetrahedra. DNA tetrahedra stiffness is about 20 MPa. This is 50,000 times less stiff as diamond. It is about as stiff as hard rubber.

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