Filtering viscous stuff (was: competent cells again!!)

Andrew Leech AndrewLeech at
Wed Jun 10 15:15:54 EST 1998

In article <Pine.SOL.3.96.980610104621.5486B-100000 at>, 
tjf11 at says...
>On Thu, 4 Jun 1998 gwallmanning at wrote:
>> trying to force THAT stuff through a membrane makes me go all weak! :-)
>> If you try it, let me know how it goes!
>I had to filter sterilise castor oil one for diluting a drug down, similar
>viscosity to glycerol....I for one would not recommend trying, you'll be
>there all day, and yuor hands will HURT.

We have to filter PEG solutions regularly for crystallography which used
to leave everyone with red rings on their hands till we got the "Grease
Monkey". This is an electrically operated regulator which attaches to a
pump, and takes reusable syringe barrels which have a luer lock. Now I
just have to sit there with my foot on the pedal, reading Usenet ;-)
instead of cursing, swearing and dropping tubes on the floor.
It's called the Grease Monkey because we have one barrel for vacuum grease,
used for making up "hanging drop" boxes.

I would heartily recommend rigging up something similar if you must filter
"sticky stuff". The minisart filters we use are rated to 6 bar burst pressure,
but 2-3 bar is usually adequate.


Email: a dotte leech atte uea dotte ac dotte uk - U-no-Y!
Andrew Leech                 *All opinions personal
Biological Sciences          *
University of East Anglia    *Economics is the eugenics of
Norwich, UK                  *the late 20th century.

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