Living computers within your body

Project leaders Maung Nyan Win and Christina Smolke have revealed that, so far, they have tested the living computer on a living yeast cell.

The researchers believe that future models of the computer, made from the DNA-like molecule RNA, may be helpful in running calculations inside human cells to release drugs, or prime the immune system, at the first hint of illness.

They have revealed that the RNA device processes input signals in the form of natural cell proteins and produces an output in the form of green fluorescent protein (GFP).

At the computers heart is a ribozyme, a short RNA molecule able to catalyse changes to other molecules, which is attached to an RNA sequence that the cell can translate into GFP, and a third RNA molecule that acts like a trigger for the ribozyme.

The team say that the trigger can be designed to bind to specific molecules inside the cell like proteins or antibiotics.

When it does, the catalytic ribozyme destroys the GFP sequence, and prevents the cell from making any more glowing protein.

The presence of an input protein stops the production of GFP. Using two trigger sections produces a NAND gate, the output of which depends on the presence or absence of two input proteins.