Freeze-drying

[Nick Theodorakis]

In article <Pine.GSO.4.05.9908131111210.6257-
100000 at cbl.umces.edu>, "Reno T. Nguyen" <reno at cbl.umces.edu> 
wrote:
>On Fri, 13 Aug 1999, KuS wrote:
>
>> Hello,
>> 
>> I would just like to know if the principles of the freeze-drying in a
>> lyophilizator and in a speed-vac machine are the same?
>> 
>> Thanks,
>> 
>> Barbara (info at kos-computers.si)
>
>
>Hi Barbara,
>
>Well, although both freeze-drying (lyophilization) and speed-vac drying
>involve pulling a vacuum on your samples, the process of removal of water
>in each instrument is different.  With freeze-drying, the samples are
>frozen, and water is removed through the process of sublimation- solid
>water is lost as a gas.  With a speed-vac, the sample is not frozen but is
>usually heated in a chamber while being spun at high rpm's; liquid water
>is lost as a gas.
>
>Reno
>

Nothing prevents you from using the speed-vac as a 
lyophilizer, however, by freezing your samples first (as I 
do).

Nick


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