1. If you spread 0.1 ml of 10-3 of a sewage sample on a plate, and obtained 221 colonies on the plate after incubation, how many CFU/ml were present in the undiluted sewage sample?
2. How can you make E.coli cells competent so that they can be transformed?
3. What is the appearance of transformed bacterial colonies?
4. After transformation procedure, your test tube may contain both transformed and nontransformed cells.
a. which will grow on LB plate? Which will grow on LB/amp plates?
(+ DNA or - DNA)
5 Why is there heavy growth on LB and very little growth on LB/amp?
5. What is the reason to plate E.coli cells on LB/amp?
6. Why are there both green and white colonies on LB/amp?