histag elution alternative

[Richard P. Grant]

In article <8tpqc8$kna$1 at news.doit.wisc.edu>, 
klenchin at facstaff.REMOVE_TO_REPLY.wisc.edu (Dima Klenchin) wrote:

> Interesting... While I do not dispute the finding (never tried 
> myself), I am puzzled. Why would it be so??? There simply 
> isn't anything in NTA-agarose that can be reduced by DTT.
> NTA is coupled to agarose through spacer via AFAIR epoxy
> chemistry (not affected by DTT), NTA itself is basicaly three 
> acetates linked together.  Sepharose is just a crosslinked 
> agarose, so it is not affected by DTT either. 

Hang on.  Where's the nickel?  I'm guessing that Ni3+ or Ni2+ gets 
converted to Nickel metal (or Ni1+) in the process we're talking about.  
(Reduction is electron gain, recalling some chemistry from a long time 
ago (-: ). Which would bugger up your acetate chelation, big time.

And although the only reference I have at home does not give the colours 
of the oxidation states, I wouldn't be surprised if blue -> murky brown 
is consistent with Ni3+ -> Ni1+/0

> Anyone wants to bet? I say that reduced Ni-NTA agarose 
> can be stripped and recharged w/o a problem. 

So, 'While I do not dispute the finding' you do, actually think that 
Cornelius *and* the manufacturer are either wrong or lying?

:->

R

-- 
The Grant Family               http://www.gerbil.org.uk/
gerbil at mac.com             http://www.xv.flyer.co.uk/
 -- 'There are no turtles anywhere' - Ponder Stibbons --