At the heart of even the most sophisticated processors are good ol' Boolean logic gates:

Johns Hopkins University School of Medicine researchers are using a technique called chemically inducible dimerization, or CID, to engineer cells to function like Boolean gates.

While there is research demonstrating logic gates using biomolecules in Petri dishes, using whole cells is a different story. Previous efforts have tried to take advantage of transcriptional machinery, but this can be a slow process often taking anywhere between minutes and days — way too long for computing.

"People like to have speedy computation," says Takanari Inoue, an assistant professor
at Johns Hopkins University School of Medicine. "We were hoping to achieve computation in cells on the order of seconds, which is significantly faster than what people have achieved thus far."

Because AND and OR gates need two different inputs, either together or separately, Inoue's team had to developed two different CID systems that didn't interfere with each other.

One CID system uses two proteins called FRB and FKBP in combination with a drug called rapamycin, which is derived from bacteria, and the second CID system uses proteins GID1 and GAI.

So far, Inoue's testing has shown that their logic gates can produce the desired responses reliably, in a matter of seconds.

More detail on their research is available in their recently accepted Nature Chemical Biology paper "Generation of Intracellular Logic Gates with Two Orthogonal Chemically Inducible Systems."

Matthew Dublin is a senior writer at Genome Technology.