The conclusion drawn from my older posts

I will discuss with my mentors about my recent results. After I prepare the PPT to be shown tomorrow, I am aware of the following points.

1. I have no need to add DNase in the replica plate to confirm that transformation occur before replica. Because the the replica plate with high concentration of ampicillin and the replica with high concentration of spectinomycin has the same layout when cells pretreated with antibiotics. Transformation must have happened before replica. Otherwise, one transformant can not appear in two different places. This result confirmed that transformation process should finished 10 h after plating.

2. The discrepancy of the layout in the replica containing spectinomycin and ampicillin in the wild type cells might imply that transformation in the wild type can still take place after replcia. However, in the mutant this ability was lost. But the layout discrepancy between replica-Amp and replica-Spt does not appear stably. It is repeatable but not always like this. Nevertheless, if the latter one is really chromosomal transformation. The chromosomal marker should be able to transform in this way. Nevertheless, I will try this simple experiment recently to see whether it is the real transformation.

3. similar effect of low concentration of ampicillin and spectinomycin on transformation has been confirmed recently. The data is better than that I get previously from the wild type. However, several conflicts come out. I can not explain which one is true which one is false. I will discuss them tomorrow.