This is the first time i have replated anything and was woundering i did 18 mason jars and 5 have came down with contaminates is this a thing that always happens ?Do a couple get contaminated along the way . It seems even when i flask seed i always get one or two. Maybe someone can give me a heads up . I use a flow hood and spray everything down with rubbing alcohol including the sealed flask and i have any tools go in 10% bleach and let the hood run for about 15 minutes then start any flasking i have to do and try not to have any flask open to long while seeding or replating.
Hi , I would use 15 % bleach for your tools , when you sterilize your media in the pressure cooker do you cover the top with tin foil ? Do you make sure your lid is not on too tight ( ajar) so that it can be sterilized ? You will need 15lbs. of pressure for a full 15 min. if you leave them sit for awhile add 5 more min. Regards
I would use heat sterilization wherever possible. Bleach is not really a sterilant, it's just a disinfectant. Some things can survive exposure to bleach fairly well. If your tools aren't absolutely sterile, than you can't rule out technique as the potential problem.
Sterilize your tools in the autoclave/p-cooker or get an alcohol lamp to flame them in the hood. Just make sure the alcohol fumes have dissipated before lighting it.