his-tag buffer

Michael Witty mw132 at mole.bio.cam.ac.uk
Wed Jun 6 10:40:45 EST 2001


On Tue, 5 Jun 2001, Dr. Artem Evdokimov wrote:

> > . . . I thought there was also some objection from the manufacturer
> > because Tris can act as an electrophile.  However, my chemistry is very
> > bad and I don't quite know how that can be bad.  Mike.
>
> Tris is a primary amine. More likely to be a nucleophile (though this
> would not matter).

Sorry Artem.  Now you know how bad a chemist I really am!  I have found
the right page of the Qiagen manual (The QIAexpresssionist) which can be
found on the net).  It says that "buffers with secondary or tertiary
amines will reduce nickel ions" (page 61).  I think what happens is that
the cobalt can slowly turn brown and leach from the column.  There is a
proceedure for recharging the column though. Mike.




More information about the Proteins mailing list