A test-tube circuit made of DNA-based logic gates can calculate the square root of numbers up to 15, using DNA replication and sequence binding to conduct computations. It’s excruciatingly slow — a calculation can take up to 10 hours — so organic laptops are not exactly in our near future. But the real breakthrough is in how this system can enable control of chemical systems.

Researchers at Caltech engineered the most complex biochemical circuit ever created from scratch, according to a new paper published today. The circuit uses DNA instead of electronic transistors to produce the on-off, and-or signals that allow a computer to conduct its calculations.