OK, so the induction of CRP-S genes experiments established clearly that the ppdA gene's CRP-S promoter isn't being induced by the growth conditions I tried. And that changes in beta-gal activity don't necessarily result from changes in promoter activity. What to do now?
To make progress in these experiments, I need better tools for manipulating genes. I want to put the ppdD::lacZ fusion into the chromosome (it's on a plasmid now) and I want to test the effect of knocking out various genes, and I want to try a 'wild' E. coli strain. All of these require recombining desired genes into the chromosome, so I need to get the recombineering technique working for me. One of the post-docs was working on this, so I just need to take up where she left off.
I also need to get back to the tests I was setting up of components of the laser-tweezers project. I was just about ready to test attaching DNA to beads (have the beads with the bound streptavidin, have the biotinylated nucleotides to put on the ends of the DNA, have the DNA prep). Separately, I need to work with the new post-doc on an antibody-based method to attach H. influenzae cells to other beads, so they can easily be pushed around under the microscope.
Ernest Rutherford: Master of simplicity, mentor extraordinaire
2 hours ago in The Curious Wavefunction