Tris buffer and the Biorad model 491 Preparative Electrophoresis

Dr. Duncan Clark Duncan at
Mon Oct 18 08:01:55 EST 1999

In article <13C84303495 at>, Dr P.P.E. Freestone
<ppef1 at> writes
>We are using a Biorad model 491 Preparative Electrophoresis cell to
>purify collagen.  To optimise our purification, we'd like to collect
>discrete peaks by connecting the cell tube outlet to a flow cell. 
>However, the problem is that the tris electrophoresis buffer that the
>491 cell uses has a similar absorbance maximum to our protein (around
>340 nm - collagen has very little UV absorbance at 280 nm).  So, does
>anyone out there know if other (non-tris) buffer systems exist which
>will still give separations around pH 7-8, and which don't absorb so
>strongly at 340 nm ? 

Can't help on the buffer but could you not just hook the whole output to
a fraction collector and collect small enough and lots of fractions
based on volume or time i.e. just treat it like column chromatography
Re-analyse the fractions by SDS PAGE to find your protein. More of a
pain with multiple gels to run but also possibly more informative. 

Sorry If I'm repeating what you have already considered and rejected.


The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

Duncan Clark
DNAmp Ltd.
Tel: +44(0)1252376288
FAX: +44(0)8701640382

More information about the Methods mailing list