California Institute of Technology computer scientists have succeeded in building a DNA crystal that computes as it grows.

This is the first time that a computation has been embedded in the growth of any crystal, and the first time that computation has been used to create a complex microscopic pattern.

The scientists showed that DNA “tiles” can be programmed to self-assemble into a crystal, using DNA “sticky ends” to bind one DNA tile to another. The result is a Sierpinski triangle built out of 0s and 1s.

To embed this algorithm in crystal growth, the scientists represented written rows of binary “0s” and “1s” as rows of DNA tiles in the crystal. To emulate addition, the sticky ends were designed to ensure that whenever a free tile stuck to tiles already in the crystal, it represented the sum of the tiles it was sticking to.

The work is the first experimental demonstration of “algorithmic self-assembly,” in which scientists study the implications of embedding computation into crystal growth.

The research is reported in the December issue of the journal Public Library of Science (PLoS) Biology.