California researchers have revealed a tiny tic-tac-toe game that uses DNA. The game shows off a major breakthrough in nanotechnology, as it uses a dynamic system to reshape tiny tiles of DNA.

"Using this mechanism, we created the world's smallest game board for playing tic-tac-toe, where every move involves molecular self-reconfiguration for swapping in and out hundreds of DNA strands ...

The Tic-Tac-Toe game circumvents this complication by using a second technique called DNA strand displacement. With this approach, scientists again exploit DNA pairing patterns.