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bacterial growth in buffers - (May/02/2011 )


I wanted to know if there is any chemical that can be used to prevent bacterial growth while making buffers containing salts like Tris,KCl?

I mean something that can be added such that long term use and storage is possible.Iam asking this because inspite of autoclaving i see bacterial growth in just two months time.

Instead of autoclaving after the buffer preparation i just autoclaved the glassware,water etc and prepared the same in laminar air flow chamber.Still growth has appeared.

Thanks if any of you could help:)


A common choice is sodium azide (toxic!!) at 0.1% concentration. Another popular one is the industrial chemical Kathon, which has the advantage of being non-toxic to mammals (although it is highly toxic to fish).


The contamination will be in the chemicals, you can autoclave both of the solutions you mentioned and many of the others. YOu are better off autoclaving the final solution than trying to keep it all sterile beforehand.

You could filter sterilize if you want to.