I wonder if you would be kind to share your how you do your in house QC of competent (E. coli) cells that you use for transformation in prokaryotic expression service? I am looking for a system to log this better, e.g. for monitoring competency.
We btw use Zymo Research' kit for making the competent cells (in no time), and we are very happy with the protocol.
I've made a form myself covering what I had in mind for quality control of our in-house made competent cells. You may download it under the "files"-section in this forum.
I am looking for a pichia pastoris strain expressing the GFP. Can somebody help me ?
I can help you with the Pichia-strain, but you may want to start a new forum topic (>Add new forum topic) on this, since now it is like a reply on my QC-topic (and maybe somewhat hidden in the forum).
We dont really check, we buy MACH1 cells from InVitrogen, for the tranformation of our ligations, so we only make competent cells of the expression strain. and they get transformed with miniprep DNA, and that (almost) always work.
We check cells with a "real" cloning test. In our case, we use LIC for cloning, so we transform the cells with a mix of vector and insert that have worked before. Testing with purified supercoiled plasmid can give misleading results.