Question

You wish to isolate a thymidine auxothrophic mutant of E.coli. Describe briefly what experiment you would do to
accomplish this.

Answer 1

you have to grow e.coli in two different culture cell. The first one due to contain thymidine as a control and the second one won't have thymidine. then in your culture without thymidine you must to add thymidine and those cells start to grow will be auxothropic mutant to thymidine