Zane and I got to pilot-test the new lab activity that incorporates the 
gene expression models I wrote last summer and fall. I found a cool activity by Robert Moss and adapted it. The students set up the wet lab part (which involves setting up 12 tubes to culture bacteria), but then the bacteria need to incubate for 85 minutes. During that time, we use the simulations to give them practice in thinking through the models forwards and backwards. At the end of the period, they interpret the results.
The goal of the lab is to distinguish between lacI, lacZ, and wildtype cultures. In the mutants lacZ is either always on (yellow) or always off (clear). But in the wildtype, it's on under come conditions and not under others, and the results demonstrate that. In the subsequent lab, the students will do an investigation that uses the techniques they learned doing this lab.
I was pleased with the outcome of the lab: it ran a little over, but under normal circumstances, I think the entire activity could fit comfortably within a single lab period. We found a couple of things that we can tweak, but I think the activity is going to work pretty well.
StevenBrewer