Molecular transistors bring bio-computers closer to reality

Stanford University researchers have made a breakthrough towards the development of biological computers that can store, retrieve and process data using chemical reactions.

Jerome Bonnet, a postdoctoral scholar in bioengineering at Stanford University, and his colleagues have built a transistor out of DNA and RNA, bringing bio-computers one step closer to reality, the Discovery News reported.

Unlike the silicon-based computers we know and use today, new type of computers will have no keyboard or monitor. Instead, a biological computer would be made of small vats of liquids — chemicals, proteins and other biological elements that work just like electronic computers.

Bio-computers could be used not only to precisely test drug reactions on diseases for example, but do so over a particular time period and save the information for retrieval or retesting later.

The component Bonnet and his team developed is a transistor, a device essential to every computing device. In silicon-based computers, transistors allow electrons to flow — or not — simple actions that produce 1s or 0s, the basic units of information in a computer. Two transistors together form a logic gate, which is what allows a computer to manage mathematical operations. A typical computer chip has millions of transistors.

The Stanford team’s biological transistor, which they dubbed a transcriptor, uses enzymes — or integrases — that act as switches to control the flow of a protein, called an RNA transcriptase.

Linking multiple transcriptors together created logic gates, just like their electronic counterparts. And just like silicon-based logic gates, these biological gates allow for both information storage and logical operations.

Using DNA and RNA at these gates could help scientists test whether cells have been exposed to a drug and if so, how that drug was distributed among the cells. Such a system could also be used to tell whether cells have started or stopped dividing when exposed to particular drug.

Bonnets transcriptors could also amplify signals. In conventional electronics that send or receive radio signals, transistors are used to amplify signals. Transcriptors could be used in a similar way to amplify a gene that codes for a certain protein, for example.

This means that cells could be manipulated a lot more precisely, making biotechnology a much more exact science.

Their research has been published in the journal Science.