Clean negative results

I've scored all my transformation plates and found no evidence of transformation. The Tet plates have no colonies at all. This could be because I used 20 µg/ml when I should have used 10; I'm checking the resistance of RR902 to see if I should repeat this transformation. The Kan plates had lots of colonies when cells were plated undiluted, but the numbers were similar for cells with and without DNA. With DH5alpha the colonies were all tiny even after two days, but quite a few of the colonies produced by the BW25113 derivative RR3015 were reasonably large.

What next? The RA is also going to repeat these experiments, using exactly the same method that gave apparent transformants previously. And I'm going to streak some of my KanR colonies onto MacConkey maltose (the recipeints are all Lac-) to see if any are crp- as true transformants should be.