Background: I have previously worked with RNA, and then we use laminar flow hoods for any work where we do plating or inoculation of cultures while applying sterile technique. I am now working in a biochemistry lab. I'm told that I can work on a lab bench, while doing basic cloning for production of plasmids in E.coli, and don't need to use a Bunsen burner as long as I apply sterile technique (and in most cases I don't see people sterilizing the bench with enthrall prior to work). However, if I do any work which relates to expression of proteins - then I should use the Bunsen-burner while applying sterile technique.
Question: Is it really so that you don't even have to use a Bunsen-burner while plating (normal E.coli: XL1-blue cells)? in this case, why? Are there not always something in the lab which can grow on kanamycin plates? We don't use white/blue screening, we simply spread XL1-blue cells onto LB plates with kanamycin - then pick a averaged sized colony to make a LB-culture. It seems to me that we are just lucky that we usually pick the right colony (which we do confirm by sequencing after mini-prep).