Team:Groningen/Promoters

From 2009.igem.org

This page shows the measurements we did of our constitutive promoters and derives approximate RPUs relative to the weakest promoter we use. For briefness the lines in the graphs use the original numbering, which can be summarized as follows:

Background

The following graphs show the optical density and fluorescence measurements for the controls. As can be seen 4 of the LB medium controls were probably contaminated, so these are ignored in the rest of the computations.

Based on the non-contaminated control measurements we find the following average background values:

• LB
  • OD600: 0.094262500378219 (A, F)
  • Fluorescence: -11.4090909090909 (A)
  • Fluorescence: -20.6136363636364 (B,C,D,E,F)
• TY
  • OD600: 0.09115113622763 (A-F)
  • Fluorescence: -9.06818181818182 (A)
  • Fluorescence: -20.05 (B,C,D,E,F)

Using the above background values we get the graphs below.

Relative promoter units

Using the computed absorbance and fluorescence values we can determine RPUs (Kelly2009) using the formula:

((d/dt)Fθ/ABSθ)/((d/dt)FJ23100/ABSJ23100)

Note that we did not test with the official reference promoter and with RFP instead of GFP, as this happened to be easily avaible. In other words, these results should NOT be compared with other computed RPU values, but only be taken as a rough indication of the relative performance of these three promoters.

Based on the data from t>400min (>24000s) the minimum, maximum and average RPU values were computed (see the "RPU total" sheet in [http://spreadsheets.google.com/pub?key=tL1vk4bsWObQyq46vPnbV-Q the underlying spreadsheet] for the raw values, before rounding):

Although the error in the RPU computations is likely to be far from Gaussian, based on the graphs the average provides a reasonable estimate.