I am growing a BSL1 E. coli strain (ATCC 8739) for use in biofilm studies with a drip flow reactor. I am a chemist/materials scientist by training, so microbiology is pretty new to me.
I have heard that ethanol can still harbor some bacterial spores and for it to actually be completely sterile it needs to be filtered at 0.2 micron or less.
Is using a 70% ethanol solution usually fine (for most bacteriology) for helping maintain a sterile environment in a biosaftey cabinet? If I were to place a (technically unsterile) 70% ethanol solution in a clean HDPE or PP spray bottle and use it to spray down the biosafety cabinet (before and after use), the unsterile but clean neoprene/latex gloves I would be wearing, and my media bottles before and after use in the cabinet, would this likely be sufficiently sterile (assuming aseptic technique otherwise)? Or should I filter the ethanol solution prior to using it in sterilizing surfaces?
Also, is IPA generally better to use than EtOH?
Thanks so much for your time and help in advance.
technical ethanol of 70% is not fully sterile but sufficiently steril for your purpose. having cleaned in this way your laminar flow bench you should put on the UV for a couple of minutes which, in general, is sufficient for maintaining sterility
Dear Amelia, firstly you should turn on UV of biosafety cabinet for 30 min then run the flow of cabinet empty at least 15 min, after cleaning the working surface with 70% Et-OH, you can work safely. In my opinion, if you want to use sterile Et-OH, you can dilute absolute Et-OH to 70% using sterile water.
Best regards.
Something is either sterile or not, there is nothing in between. Alcohol makes some bacteria and virus inactive because it lowers the water activity. More chaotropic agents (eg. hypochlorite or glutaraldehyde) kill faster but even they need some contact time to be effective.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3194873/
- Badges
- Science topic
- Similar topics
- Biological Science
- Botany
- Plant Biology