recovery of freeze dried bacteria - (Mar/31/2014 )
could you pls help?
i have freeze dried bacteria and i need to reconstitute. I will place them in BHI broth for overnight then streak the bac onto blood agar and again for an overnight. what is the best way to preserve the bacteria since i will be working for few months on my experiment and i need to preserve it in enough stock.
Freeze dry them.. lol
Freezeydring is a method to preserve bacteria.... Its also usefull to ship them to other people.
Normally you should have enough freezedried sample to store them freezedried... (I would thus not use the entire freezedried sample to revive them).
The part of the sample you used to revive them: just pick a colony from those cells (or a few colonies, not sure what you are doing and what kind of sample it is, I suppose its from a single colony?) and store that in -80 in glycerol (make more than 1 aliquot).
thx for the reply . Do i need to grow a broth culture overnight in BHI then centrifuge and resuspend pellet in BHI in glycerol after the step of reviving them on blood agar. what is the additional benefit of this way (to resuspend in BHII again then centrifuge etc..)?
would be great to understand this.
some people dont even revive in broth. They just use a little bith of broth , let this "incubate" for a few hours and then add this to agar plates (so they skip that double step you have).
Your way is also fine.
The second step, using the agar plates, is something you do to pick 1 single colony. This colony is picked and used to make your stocks.
+ by plating it out you can see if everything is ok... (eg if there is some contamination, other defects...) SO you need to plate it to make sure you are working with good cells.
big thank you!