From 2010.igem.org

Design Choices

Promoter: PyeaR

Proteins involved native in most 'E. coli' strains.

Doesn't depend on metabolic state of bacteria (i.e. doesn't require anaerobic environment).

Already available in parts registry.

Signal: GFP

Easily detectable with relatively low tech equipment.

Quantifiable signal.

Doesn't require any substrate (as opposed to luciferase).

Wide range of fluorescent proteins available in parts registry; allows us to easily extend project by connecting these to other promoters, without needing additional detection equipment.

Chassis: MG1655

Minimally engineered; meaning chassis robust enough to survive in the environment, without posing a public health hazard.