The European Patent Office has awarded a patent to gene synthesis company Genearts for a technique to perform directed evolution in vitro instead of in vivo. Published in April last year, the patent describes a technique that, in effect, puts an evolutionary feedback loop inside a test tube.
The Genearts work is broadly similar to that of teams led by George Church at Harvard and Andrew Ellington at the University of Texas at Austin – both are pursuing the idea of transferring key enzymes out of cells where they can be more easily controlled.
According to the patent, which is written in German, the Genearts techniques revolves around the use of both an RNA polymerase to transcribe DNA and a reverse transcriptase to write new DNA. It's a variant of a process that has been put forward as an alternative to the ubiquitous polymerase chain reaction (PCR).
The process uses reverse transcriptase to produce more DNA of a favoured mutant protein in the tube than the original protein or less well-adapted mutants.
They do this using a molecule that attaches itself to the polymerase and which also binds preferentially to favoured mutant proteins. This molecule acts as a primer that allows reverse transcription to begin. Potentially, the molecule can be based on RNA or be a protein or peptide.
Genearts said it has applied for a similar patent in the US.
