Teflon pump/gel driers

Bryan L. Ford fordb at bcc.orst.edu
Mon May 5 07:58:50 EST 1997

Ian A. York wrote:
> We just got a teflon-coated vacuum pump for our SDS-PAGE gel drier.  As I
> undrstand it, the point of the teflon pump is that it is not affected by
> the corrosive vapours produced as the SDS-PAGE gels are dried (I presume
> those vapous would include things like acetic acid, methanol, stuff from
> the flours, and so forth).  My question is, what kind of precautions *do*
> i need to take with the pump?  I'm guessing that we no longer need to
> provide the cold trap that most gel driers are set up with in one form or
> another. Should I put a couple of flasks between the drier and the pump,
> so that liquids and particulates can condense out?  A couple of flasks
> with DriRite in one or both?
> If there a potential health hazard with vapours being pumped into the lab?
> We don't take any special precautions around the gels themselves (other
> than the obvious ones, like not sticking our tongues in the liquid); would
> the vapours be of more concern?
> Anyone have experience with these pumps?


We have used such a pump extensively (an "ABM" made in Germany,
distributed by Elnik in the USA). In defiance of our rudimentary
understanding of vacuum thermodynamics, we have empirically found that
the pump works much better and faster if we include the usual ice slurry
cooled vapor trap (only one flask)ahead of the pump. Such an arrangement
might be advisable in any case if one is drying down sulfur
35-containing gels, and it gives one a sense of security with other
isotopes as well. Our pump has performed flawlessly under fairly harsh
conditions for several years now.

Hope this helps you.

Bryan L. Ford

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