A computer made from DNA-coated beads could detect viruses in saliva

By Carissa Wong.

A type of DNA computer that shows results through the motion of tiny beads could vastly increase the parallel processing power of such machines.

It is possible to work in wet environments with DNA computers. They could be used to monitor sugar levels in the body.

The previous designs used fluorescent labels to show results, but could only output tens of results at a time. Complex microscopes are required to read the findings.

One hundred-fold is a conservative estimate of how much more parallel processing we can do with our DNA computer compared to fluorescent labels.

Salaita and his colleagues made computers out of glass microbeads that roll or stall on the surface of a gold chip depending on how the DNA strands interact with the molecule attached to the chip. Rolling is equivalent to an output of 1, while stalling is equivalent to an output of 0.

The results of the computation can be seen by using a camera on a phone with a magnifying glass.

That is the wild thing. Salaita says that you can convert the information from the DNA computational operation to the world using a standard phone in 15 minutes.

Read more: DNA computer could tell you if your drinking water is contaminated

The team created a guide that can bind to the chip surface. When this happens, the beads stay still, but when an enzyme called RNaseH is added to the chip, it allows the beads to roll.

The presence or absence of a specific DNA molecule can be controlled by a computer. The presence of the DNA molecule halted the bead, but its absence allowed it to roll. The system can be adapted to detect any interest in the environment.

The computers could output thousands of read-outs in parallel as there are thousands of different shapes and sizes of microbeads. The device could be used to determine if you have a disease such as swine flu, or if you have another disease such as flu.

The lifespan of the computers can be limited by the fact that the chip surface can degrade after 24 hours.

Nature Nanotechnology is a journal.