Comparaison -20°/ -80°C - (Jun/08/2007 )

Hi guy's I have a basic question for you.

Does anyone know what's the real difference to conserve biological materials in -20°C compared to -80°C?
Because when it's frozen what can be different???

Thanks a lot

biofred

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some glycerol stocks (depending on percentage of glycerol) do not freeze solid at -20°C but only at -80°C; in some cases to conserve biological activity (Ab binding activity, enzyme activity etc) it is recommended to freeze as a non-solid fluid

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Stored samples or solvent such as methanol in -20°C will be easily heat up to 0°C if you handle few minutes outside. If possible, storage at -80°C is better, but more expensive.

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at -20 there may be some molecular motion at -80 there will be less, if any.

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the biological activity is considered to be completely aborted at -70°C. So -80° is for more safety.
At -20°, pronteins loose activity, and RNA degrades.... not at -80° (assuming no freeze/thaw cycles)

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