Exeter/26 July 2013

Results from transformation

The OmpR BioBrick and lambda inverter system never transform, but why? We can come up with a reasonable explanation for OmpR; the OmpR protein is already present in E. coli, and is involved with osmotic regulation. Inserting a high-copy number plasmid with the OmpR gene included and creating far more OmpR in the bacteria than is normally present is probably killing the cells. We'd initially assumed, on our first transformation, that we'd plated our bacteria onto the wrong antiobiotic, but this would not have been possible in the subsequent transformations (we've been very cautious ever since!).

However, we are still struggling to explain the failure of the lambda inverter system. We have looked at a multitude of papers, and the cI repressor protein coded for by BBa_Q04510 shouldn't have any effect on the cells, and yet...

Take me back to the notebook.