Freeze Dryer vs Speed Vac
Dorit Grunberger
speedvac to a lyophilizer both as source of vacuum and no less important, a
cold environment to keep my extract happy. I¹m doing chloroform : methanol :
water extracts of small tissue samples. The total volumes for extraction
will be small and I was hoping to use a speedvac to dry/concentrate my
MeOH/H2O phase. It¹s critical for the sample to remain as cold as possible,
since the analysis of contents is done by NMR and we¹re hoping to maintain
integrity of some very easily degradable metabolites (phospho-choline for
example).
Bottom line: do you think this will work?
Thanks in advance for any help.
Dorit Grunberger
Department of Radiology
email: dorit.gr...@radiology.ucsf.edu
415.514.4845 office
415.385.0977 cell
415.514.2550 fax
jps
work. However, I'd be worried about the temperature of the sample in
the speed vac, some older units I've worked with tend to let the
sample get fairly warm ~30oC, and I wonder if it would be any more
efficient than just using the lyophilizer as is - no speed vac. One
could set up an dry-ice/acetone bath and place a liquid nitrogen cold
trap between the frozen sample, maintained in the bath, and vacuum
pump, but that would also be equivalent to the lyophylizer plus the
time it would take to hunt down all the glassware, dry ice and acetone
for the task - not to mention the waste handling.
That's my 2cents. Good luck.
JPS
On Jul 14, 9:33 pm, Dorit Grunberger
> email: dorit.grunber...@radiology.ucsf.edu
Dr Engelbert Buxbaum
<dorit.gr...@radiology.ucsf.edu>:
> Saw this online and thought to ask you if it makes sense to hook up a
> speedvac to a lyophilizer both as source of vacuum and no less
> important, a
> cold environment to keep my extract happy. I¹m doing chloroform :
> methanol :
> water extracts of small tissue samples. The total volumes for extraction
> will be small and I was hoping to use a speedvac to dry/concentrate my
> MeOH/H2O phase. It¹s critical for the sample to remain as cold as
> possible,
> since the analysis of contents is done by NMR and we¹re hoping to
> maintain
> integrity of some very easily degradable metabolites (phospho-choline for
> example).
The lyophiliser keeps samples cold by the heat of evaporation that is
constantly removed from the system. As long as your vacuum is strong
enough and the solvent has not evaporated the sample will be at a
temperature well below its freezing point. If there is a problem you
recognise that by your sample melting.
In the SpeedVac the lyophilisation process is speeded up by gently heating
the sample to replace the heat of evaporation, the sample will not be
quite as cold as in a lyophiliser. In addition the residue will be in a
small spot due to the centrifugal force, it will be easier to take it up
in a small volume later. In addition, loss of residue will be smaller
(important e.g. for radioactive samples).
In either case sensitive samples have to be removed immediatly after
complete drying, as they will warm to room temperature (or to operating
temperture in the SpeedVac) once no solvent evaporates anymore.
allisonh
in a cold room (with the heater turned off of course).
Allison
Dorit Grunberger wrote:
> Saw this online and thought to ask you if it makes sense to hook up a
> speedvac to a lyophilizer both as source of vacuum and no less important, a
> cold environment to keep my extract happy. Iım doing chloroform : methanol :
> water extracts of small tissue samples. The total volumes for extraction
> will be small and I was hoping to use a speedvac to dry/concentrate my
> MeOH/H2O phase. Itıs critical for the sample to remain as cold as possible,
> since the analysis of contents is done by NMR and weıre hoping to maintain
jps
> If a cold temperature is important maybe you could just run the Speedvac
> in a cold room (with the heater turned off of course).
> Allison
>
>
>
> Dorit Grunberger wrote:
> > Saw this online and thought to ask you if it makes sense to hook up a
> > speedvac to a lyophilizer both as source of vacuum and no less important, a
> > water extracts of small tissue samples. The total volumes for extraction
> > will be small and I was hoping to use a speedvac to dry/concentrate my
> > since the analysis of contents is done by NMR and we¹re hoping to maintain
> > integrity of some very easily degradable metabolites (phospho-choline for
> > example).
>
> > Bottom line: do you think this will work?
>
> > Thanks in advance for any help.
>
> > Dorit Grunberger
> > Department of Radiology
> > 415.514.4845 office
> > 415.385.0977 cell
> > 415.514.2550 fax- Hide quoted text -
>
> - Show quoted text -
Here's another question along these lines: canthe lyophylization
process itself does not denature your protein?
Dr Engelbert Buxbaum
> Here's another question along these lines: canthe lyophylization
> process itself does not denature your protein?
Potentially yes, that depends on the protein and the exact conditions
used. Companies have entire departments that develope suitable protocols
for lyophilising and reconstituting proteins of interest. This is black
art, not science. Sometimes addition of polyols like trehalose helps.