Qiagen/Nucleobond Cartridge Reuse

Jim Woodgett jwoodget at oci.utoronto.ca
Thu Aug 18 10:19:20 EST 1994

In article <CupCn3.5z9 at world.std.com>, nestgrp at world.std.com (Amos H 
Heckendorf) writes:
> Several of you have inquired as to why Qiagen or Macherey-Nagel suggest 
> a limited period of time within which to reuse your cartridges for 
> plasmid preps.  This is the explanation for Nucleobond and since 
> the products are nearly identical, separate patents not withstanding, 
> the explanation will fit both. 
> The products are silica based and as such the elution conditions of pH > 
> 8.0 would dissolve the silica in the matrix upon long storage at 
> these conditions.  With the normal allowance for German 
> English translation, the reasoning on a 3 hr or one day period is 
> the following: 
> 1.  less than 3 hrs will assure silica will not have dissolved if 
> you nonchromatographers have left the cartridges in the high pH buffer. 
> 2. less than assumes that you washed the cartridges with at least 5 
> column volumes of water and equilibrated the cartridges in the 
> pH 6.3 buffer and then left the cartridges around.  The one day 
> would assure that the cartridges would not have dried out or formed 
> air pockets which would prevent good access to the surface 
> chemistry, which would result in lower yields. 
> 3. you could wash the cartridges off with ethanol:water 50:50 and 
> store them and when ready to reuse repeat the wash prior to 
> equilibration with the binding buffer.  This would prevent 
> bacterial growth on storage, it would wet the surface for intimate 
> contact of the buffer and would lower your cartridge consumption.  Do 
> you really think they want you to do that? 
> If you want to try the Nucleobond, give me a call 800-347-6378. 
> Regards, 
> Amos (nestgrp at world.std.com) 

Amos, despite your helpful comments you really should explicitly declare your 
interest in these products as you are posting from a company that markets one 
of them. This is standard netiquette and can help prevent misunderstanding, 
conflict of interest, etc.

I might add that the two products you mention work equally well in our hands 
and I am looking forward to some active competition to reduce the prices 
further and thus extend my grants  ;-)



(who has no affiliations with Diagen, Macherey-Nagel or the Nest Group)

P.S. Please don't use follow-ups to this message to increase your companies 
exposure.  I'm sure you will be a good net citizen from now on.......

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