Probing cell-free gene expression noise in femtoliter volumes

Journal Article · Tue Jan 01 04:00:00 EST 2013 · ACS Synthetic Biology

DOI:https://doi.org/10.1021/sb400028c· OSTI ID:1095144

Karig, David K ^[1]; Jung, Seung-Yong ^[1]; Srijanto, Bernadeta R ^[1]; Collier, Pat ^[1]; Simpson, Michael L ^[1]

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1. ORNL

Cell-free systems offer a simplified and flexible context that enables important biological reactions while removing complicating factors such as fitness, division, and mutation that are associated with living cells. However, cell-free expression in unconfined spaces is missing important elements of expression in living cells. In particular, the small volume of living cells can give rise to significant stochastic effects, which are negligible in bulk cell-free reactions. Here, we confine cell-free gene expression reactions to cell relevant 20 fL volumes (between the volumes of E. coli and S. cerevisiae), in polydimethylsiloxane (PDMS) containers. We demonstrate that expression efficiency varies widely at this volume, and we analyze gene expression noise. Noise analysis reveals signatures of translational bursting while noise dynamics suggest that overall cell-free expression is limited by a diminishing translation rate. In addition to offering a unique approach to understanding noise in gene circuits, our work contributes to a deeper understanding of the biophysical properties of cell-free expression systems, thus aiding efforts to harness cell-free systems for synthetic biology applications.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1095144
• Journal Information: ACS Synthetic Biology, Journal Name: ACS Synthetic Biology Journal Issue: 9 Vol. 2; ISSN 2161-5063
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English