Reproducibility of Fluorescent Expression from Engineered Biological Constructs in E. coli

PLoS One. 2016 Mar 3;11(3):e0150182. doi: 10.1371/journal.pone.0150182. eCollection 2016.


We present results of the first large-scale interlaboratory study carried out in synthetic biology, as part of the 2014 and 2015 International Genetically Engineered Machine (iGEM) competitions. Participants at 88 institutions around the world measured fluorescence from three engineered constitutive constructs in E. coli. Few participants were able to measure absolute fluorescence, so data was analyzed in terms of ratios. Precision was strongly related to fluorescent strength, ranging from 1.54-fold standard deviation for the ratio between strong promoters to 5.75-fold for the ratio between the strongest and weakest promoter, and while host strain did not affect expression ratios, choice of instrument did. This result shows that high quantitative precision and reproducibility of results is possible, while at the same time indicating areas needing improved laboratory practices.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Green Fluorescent Proteins / biosynthesis*
  • Green Fluorescent Proteins / genetics
  • Laboratory Proficiency Testing
  • Promoter Regions, Genetic
  • Protein Engineering
  • Reproducibility of Results
  • Transcription, Genetic
  • Transcriptional Activation


  • Green Fluorescent Proteins

Grants and funding

Raytheon BBN Technologies, Synthace, and Agilent provided support in the form of salaries for authors JB, MG, and JH, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the author contributions section.