1) We all know that bacteria could be preserved for longer period in 50% glycerol stock at -20C, but could anyone suggest, what would be the effect if we store glycerol stocks at -100C to -180C.

Would it be beneficial or could kill our cultures?

2) What would be the effect on competent cells which comes with the invitrogen kit like Top 10 E coli cells, if it is stored at -130C to -180C instead of -20C/-80C. what would be the effect of such a low temperature on cells competency.

Actually someone has told me that it is better to store cultures at lower temperatures, and more beneficial would be if you store in liquid nitrogen.

Hi there!

I don't know about liquid nitrogen but I would never store my bacteria at -20°C, always at -80°C!

Stardust

Why not do the experiment?

great suggestion - this is why we love you, Swanny!

I did my thesis on the preservation of fungi.

I might be able to give you some information on preservation in general.
I have a lot of textmaterial, I'll be able to search in it and maybe send you some papers regarding the preservation of fungi and bacteria.

If you are intersted let me know.

However keep in mind that I am very bussy at the moment and might not be able to answer or send the textmaterial right away.

cheers