Microchips to mimic living cells

A microchip that can generate microdroplets for protein and nanoparticle synthesis.

July 2013

Together with MCN, Technology Fellow Yonggang Zhu and his team from CSIRO have successfully developed a microchip that mimics a living cell by housing millions of tiny water droplets which synthesise enzyme molecules. This is a critical step towards fast-tracking low cost protein development.

They have successfully developed a microchip that can produce millions of tiny water droplets inside itself. These droplets contain necessary materials like those in a living cell, while enzyme molecules are synthesised in each droplet. The unprecedented speed of synthesis can potentially solve some of the bottle-neck problems in protein evolution.

The team has studied the physics of fluid flow at microchannels and designed a microchip that can flow two immiscible flows i.e. water and oil, for generating monodispersed water-in-oil microdroplets. The microchip was fabricated at MCN using polymeric materials instead of silicon. The plastic microchip has the function of sequentially generating microdroplets for compartmentalising biological reagents, performing in-drop in vitro transcription and translation reactions, fusing droplets for on-chip enzyme assays and detecting in-droplet biochemical reaction products.

The microchip format allows the generation of millions of enzyme assay droplets per day, which is an unprecedentedly high throughput none of the currently commercially available equipment can match. The progress Dr. Zhu’s team has made in microchip-based enzyme synthesis and screening is significant. Since tiny amounts of sample solution is required and a high throughput can be achieved, this could potentially allow researchers to screen and select libraries of massive numbers (from millions to trillions) of candidate gene/protein variants, from either natural sources or synthetic ‘in vitro evolution’ experiments, a critical step to fast track the protein development with low cost.

The technology could potentially allow biologists to develop new proteins (e.g. enzymes) within days instead of years and with a cost of hundreds of dollars instead of millions and billions of dollars. This will benefit many areas in biotechnology, medicine and environment.

You can read more about this work in Enzyme synthesis and activity assay in microfluidic droplets on a chip, published in Engineering in Life Sciences.