Part Types:Measurement Systems

Promoter Output High Measurement Systems

Show the table of output high measurement systems

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These systems allow measurement of the relative strength of a promoter when it is not being repressed. They all require external validation of the operating conditions such as plasmid copy number and cell metabolism.

Other Measurement Systems

Show the table of other measurement systems

Methods of measurement are central to all forms of systems engineering. Specifically, we would like to be able to build systems using standard parts that when combined have reliable and predictable behavior. Here we define standard characteristics for describing the absolute physical performance of genetic parts that control gene expression.

Quantification Types

These are definitions of some methods currently being used to evaluate Biobrick performance

PoPS and RiPS

The quantification of Biobricks via PoPS ([RNA] Polymerase Per Second) and RiPS(Ribosomal initiations Per Second) is a current project of Caitlin Conboy of the Endy Lab at MIT.

PoPS, defines the level of transcription as the number of RNA polymerase molecules that pass a point on DNA each second, on a per DNA copy basis (PoPS = Polymerase Per Second; PoPSdc = PoPS per DNA copy). The second characteristic, RiPS, defines the level of translation as the number of ribosome molecules that pass a point on mRNA each second, on a per mRNA copy basis (RiPS = Ribosomes Per Second; RiPSmc = RiPS per mRNA copy).
In theory, it should be possible to routinely combine devices that send and receive PoPS and RiPS signals to produce gene expression-based systems whose quantiative behavior is easy to predict. To begin to evaluate the utility of the PoPS and RIPS framework we are characterizing the performance of a simple gene expression device in E. coli growing at steady state under standard operating conditions; we are using a simple ordinary differential equation model to estimate the steady state PoPS and RiPS levels.


  • Conboy et al. "Definitions and Measures of Performance for Standard Biological Parts" link