Dialysis device

D.K. dk at no.email.thankstospam.net
Mon Oct 29 08:25:09 EST 2001

bkclo at yahoo.co.uk (BL) wrote:
>In additional to soft dialysis tubings and those membranes mounted on a
>frame, does anyone know of any other types of devices for dialysing a
>small sample? I need to dialyse a small sample which I don't want to put
>into a dialysis tubing or have to use a syringe to put into the membrane
>device (for fear of shearing the sample). A rigid tube with a wide enough
>opening (so that I can pipette in the sample) that has low adherence to
>proteins would be ideal. thanks for any suggestions.

This is what I was taught at least 15 years ago: 

Find an eppendorf tube with flat cap and nice, deeply protruding
"walls" on the cap. Cut small hole in it, enough to pipet the sample
in and out. Cut the upper part of that eppendorf tube's neck so that 
it's width is less than that on the cap above. Then you take wet membrane, 
lay it on the cap and snap firmly with the "ring" cut from the tube. 
Carefully cut excess membrane around - then the device will float 
nicely in ther correct orientation. That's it - perfect dialysis for 
20-100 ul volumes. 

I think Pierce recently started to sell a version of this. You can also
ask your local crystallographer for "dialysis buttons". They are 
great, but can be tricky to use. 


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