In article <[email protected]>, [email protected] says... > > In article <[email protected]>, > =?iso-8859-1?B?UGVwYSBGbG9yZXogUOlyZXo=?= <[email protected]> > wrote: > > > have discovered today that one of our prepacked gel filtration > > column is ompletely dried out. e have tried to make it work by > > re-hydration and the pressuere has decreased but it is stil very > > high. > > > > o you know if it is possible to make it work in the same way as > > before? > > If it is sugar polymer-based (agarose, dextran) then no, a massive dry > out is irrepairable. The reason is, even though modern matrices are > highly cross-linked, upon drying granules collapse and that is pretty > much it. > > Dried silicagel or resin columns (used mostly in HPLC) would be no > problem - wash extensively with degased buffer with the outlet up for > the air to escape, then wash with methanol that will very efficiently > dissolve air still trapped.
If the particles dried out, yes, the gel is lost. However, that takes quite a while (weeks or months). Usually, only the fluid in the space between gel particles is replaced by air, and then the column can be rescued. However, it needs to be unpacked, the gel resuspended in buffer, the "fines" removed, remaining gel de-aerated with vacuum, and re-packed. This needs to be done according to manufacturer's instruction for the gel (packing funnel, correct flow rate/pressure etc.). You may need an adjustable end-piece, as you are likely to loose some part of the gel volume. Do not try to just pump buffer into the dried-out gel bed! It is unavoidable that air bubbles and cracks remain, this will seriously lower the resolution of the column. _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
