Stanford University bioengineers have developed the first biological transistors made from the genetic materials DNA and RNA.
The instruments, called "transcriptors," are the final piece in the puzzle of making biological computers that work inside of living cells. This type of computer would be able to notice alterations in a cell's environment, store a record of the alteration and then produce a response, like telling a cell to stop creating insulin or to self-destruct if cancer is present.
"Biological computers can be used to study and reprogram living systems, monitor environments and improve cellular therapeutics," said Drew Endy, assistant professor of bioengineering and senior author of the paper, in a press release.
Transistors are an essential component of any computing device. They control electron flow over a circuit in silicon-based computers, an operation that produces binary code, the basic units of computer information. Together, two transistors produce a logic gate, allowing the computer to handle mathematical equations. Typically, a computer chip contains millions of transistors.
In a similar fashion to a transistor, the transcriptor controls the flow of the protein RNA polymerase as it moves across a DNA strand. The researchers were able to alter the purpose of some natural proteins called integrases, allowing for digital control over the flow of the RNA polymerase. Accordingly, they were able to create amplifying genetic logic.
The transcriptors can allow for some incredible accomplishments. The scientists have been able to use them to create logic gates, allowing for true-false processing of biological questions within a cell. They call these gates "Boolean Intergras Logic" gates or BIL gates.
The scientists were able to accomplish this by measuring groups of the integrases that control RNA polymerase flow. They made a selection of integrases that operate within plants, animals, bacteria and fungi so that future bio-computers could be created in a number of organisms.
"The potential applications are limited only by the imagination of the researcher," said co-author Monica Ortiz in a news release.
High-functioning biological computers will probably not arrive any time soon; however, simple biological sensors are certainly a possibility in the near future. Because Stanford has added the BIL gate design to the public domain, other research institutes should also be able to start working on a biological computer.
The possibilities of actual biological computers are enormous. They could be used to warn about disease and also as diagnostic devices. By telling cells what to do, they will likely make a good number of pharmaceutical drugs unnecessary.
"Most of biotechnology has not yet been imagined, let alone made true. By freely sharing important basic tools, everyone can work better together," said researcher Jerome Bonnet in a news release.
The study is published in the journal Science.
