[bionet.molbio.methds-reagnts] Vacuum pumps for gel drying

wrp@biochsn.acc.Virginia.EDU (William R. Pearson) (05/29/91)

	Savant, the people who make Speed-Vacs, have introduced a pump
designed for gel-drying and similar problems, where a large amount of 
potentially corrosive liquid is removed.  It is a diaphram pump with no
oil.  Unfortunately, it costs around $1500.  Looks like it would do
the job.

Bill Pearson

PHILLIPSA@lars.afrc.ac.uk (05/29/91)

I've never been in a laboratory which has a wholly satisfactory
system for drying polyacrylamide and agarose gels. The BioRad gel
dryers are fine, it's the vacuum pumps which present the problem.
Most labs I've been in use in-line vapour traps to remove the corrosive
solvents, but these don't seem to be very efficient and the vacuum pump
has a limited life even with frequent oil changes. Our present system
uses an Aquavac, which (as I understand it) is a water vacuum pump driven
by high-pressure water. This is OK, but doesn't give the greatest vacuum
and ours needs replacing anyway.
To get to the point, I've come across literature for a pump made by
Genevac, which uses a Cole pump system. This seems ideal (although not
cheap), as it has few moving parts and is highly corrosion-resistant.
Has anyone experience of this type of pump with corrosive vapours?
Can someone recommend a better system?

Thanks for your help

Andy Phillips
Long Ashton Research Station, Bristol, UK
JANET: PHILLIPS@UK.AC.AFRC.LARS
EARN/BITNET: PHILLIPSA@LARS.AFRC.AC.UK

donnel@helix.nih.gov (Donald A. Lehn) (05/30/91)

In article <9105291140.AA01516@genbank.bio.net> PHILLIPSA@lars.afrc.ac.uk writes:
->I've never been in a laboratory which has a wholly satisfactory
->system for drying polyacrylamide and agarose gels. The BioRad gel
->dryers are fine, it's the vacuum pumps which present the problem.
->Most labs I've been in use in-line vapour traps to remove the corrosive
->solvents, but these don't seem to be very efficient and the vacuum pump
->has a limited life even with frequent oil changes. Our present system
->uses an Aquavac, which (as I understand it) is a water vacuum pump driven
->by high-pressure water. This is OK, but doesn't give the greatest vacuum
->and ours needs replacing anyway.
->To get to the point, I've come across literature for a pump made by
->Genevac, which uses a Cole pump system. This seems ideal (although not
->cheap), as it has few moving parts and is highly corrosion-resistant.
->Has anyone experience of this type of pump with corrosive vapours?
->Can someone recommend a better system?
->
->Thanks for your help
->
->Andy Phillips
->Long Ashton Research Station, Bristol, UK
->JANET: PHILLIPS@UK.AC.AFRC.LARS
->EARN/BITNET: PHILLIPSA@LARS.AFRC.AC.UK

Regarding your input for information on the Genevac.  We have a Genevac pump
model number CVP100/2 in our lab here at the National Institutes of Health.
Based on how well this pump works and the type of service we have had from the
company I feel you would have to be a complete fool to believe that this
product actually works.  In the 18 months that we have had the pump it has
actually worked for a total of not more than 116 hours.  This is not because
we do not use it but because the pump has broken down virtually every time we
have tried to use it.

The service from Genevac is even less efficient than their pump.  The pump
originally stopped working several hours after the company service rep came 
to the lab and set it up.  It took more than 6 weeks before we could get the
pump serviced.  After the pump was serviced, a small hose broke on the pump
broke and it took more than 2 months in order to get a replacement.  Currently,
the pump is once again down.  We called Genevac several months ago in order to
have it serviced and we are still waiting for the repair man.

Based on my experience with Genevac and their poor service record, I would
highly recommend against dealing with this company.  If you need a reliable
vacuum system, buy a traditional high quality vacuum pump and put on it the
filter system sold by Svant.  I have found that the Savant filter system is
excellent in protecting the pump connected to a gel drier.

Best regards,
Donald A. Lehn
National Institutes of Health

Email: donnel@helix.nih.gov

BROE@AARDVARK.UCS.UOKNOR.EDU (Bruce Roe) (06/01/91)

Fellow Netters,

	With this discussion of refrigerated traps and pumps for gel drying,
thought I'd put in my 2-cents worth.

	We have two FTS-system Multi-Cool Refrigerated traps on two separate
gel dryers and they satisfactorly protect the pumps *if* we perodically change
the oil.

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