Team:BIOTEC Dresden

Factory-on-a-chip: Temporal and spatial control of protein synthesis by in vitro recombination inside picoliter reactors

Organizing matter on micro- and nano-scale requires specialized tools that control how components are assembled, when and where they are added, and how the product is transported. Our factory-on-a-chip is designed to do just that. In this project we conduct a two-step assembly process of biological and metallic components in microvesicles of picolitre reaction volumes.

Production and packaging in picolitre reactors allows for precise control of all components of the product. The reactors are vesicles moving through a microfluidic chamber. The transparency of the reactors and flow chamber enables us to monitor the whole production process. Enclosed in the vesicles are a synthetic in-vitro transcription-translation kit, a plasmid coding for a genetic timer and a modified protein, as well as raw materials for silver nanoparticles.

The genetic timer determines the onset of transcription and marks the beginning of the production process. It is a genetic circuit based on Flp recombinase. The timer is set off depending on the distance between two recombination sites. A genetic timer allows to add components sequentially or at a specific time.

The protein we express is a GFP tagged with a sequence which is known to nucleate silver nanoparticle formation. An engineer should be able to use any raw material for his product to have the desired properties. Yet traditionally, there is a pronounced distinction between classical and biological engineering. We try to overcome this schism by integrating protein expression and sequence-specific metallization of our modified protein with silver in one manufacturing process.