From 2010.igem.org

Testing Beads in Soil

With the beads known to be functional in soil we then began examining their behaviour on soil. Beads encapsulating MG1655 transformed with BBa_K381001 were placed on soil saturated with 6mL of ddH2O and soil saturated in 6mL of 20mM of Potassium Nitrate. These beads were then photographed using the stereomicroscope, then left for 5 days under conditions mimicing day progression (light/ dark oscillations).

The same beads were then photographed again and the images analysed using ImageJ.

We were pleased to note that the beads subjected to nitrogen were fluorescing considerably more [insert figure here] than they had been 5 days earlier, evident in the figure below.

[insert bead comparison]

unfortunately, we realised it was not possible to compare different beads due to probable differences in the number of bacteria encapsulated. It was for this reason that we decided to implement our ratio method.