Hybond N Problems

sunil shaw skshaw at mbcrr.harvard.edu
Mon Aug 19 15:49:47 EST 1996



Is it okay for a company to change the basic formulation of a product, 
but to market it under the same name? At least if they were to say
'new, improved' or something like that, users would have warning
of potential differences.




Mike Gruidl (mgruidl at com1.med.usf.edu) wrote:
: Dear Netters:

: Just thought I would pass along a little bit of info.

: Amersham has had to change the way they make Hybond N.  Unfortunately, this may give 
: some problems with background.  Amersham readily acknowledges that about 30% of their 
: end users have experienced a problem.  I was part of that 30%.  

: I had routinely used a pre-hyb of 2x denhardt's, 5x SSC and a hyb mix of 2x denhardt's, 
: 5x SSC, 0.3% SDS and Salmon sperm.  No problems with the old formulation but every blot 
: with the new membrane gave a tremendous blotchy background which could not be removed by 
: stringent washing (0.1% SSC, 0.1% SDS at 65oC).  I stripped the membranes in boiling 
: 0.5% SDS but the background is still present.  

: Another co-worker in the lab uses a different hyb solution which includes pyrophosphate 
: and he does not have a problem.  I reprobed one of his blots with my standard protocol 
: and I also had no problem.  

: For the record, Amersham now recommends using the Church buffer recipes for 
: hybridizations.  I have just done another set of Northern blots following their advice. 
:  I'm just guessing, but I believe that the increased amount of negative charge from the 
: SDS and the phosphate should prevent the non-specific binding of my probe to the "bad" 
: spots on the membrane.

: I would be interested in getting some feedback from others who might have had similar 
: problems and how they managed to correct them.

: I would also be interested if anyone else is interested in developing a specific forum  
: for posting 'verifiable' problems with any companies product.  I have had several 
: incidents where a product was purchased and the company does nothing to warn the end 
: users of potential problems.  I would assume that would be a bad policy to call 
: attention to any defect in a product.  I don't see anything wrong though with the end 
: users calling others attention to those defects.  It might improve or get rid of those 
: selling bad products (like oligos and antibodies, just to name two of the worst 
: offenders).  Any reputable company will probably welcome the spotlight.  What do you 
: think?

: Mike Gruidl

: All of these opinions are mine, not that anyone would want any of them.



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