Maleic acid buffer: Help me make it

[Rich Kernan]

In article <scj-1502960907510001 at jmm3.ahabs.wisc.edu>,
scj at calshp.cals.wisc.edu (Scott C. Johnson) wrote:

> I have long used the Genius detection system, however, B-M has changed
> things on me a bit. Namely, one of the new buffers calls for 100mM Maleic
> acid, 150mM NaCl, pH 7.5. Seems easy right. Well, the 1x buffer is, only
> problem is that you need alot of it, and a 10x stock would be much more
> convenient. B-M sells a 10x stock, but there's not much sense in buying
> the buffer, when it's easy to make, or so I thought. Before I describe the
> problem, I'll tell you that I've been on the line with B-M tech services
> several times, and they cannot solve it. Although they can make the
> buffer. 
> 
> (rest deleted)
> 
> Thanks,
> Scott
> 
> -- 
> Scott C. Johnson
> AHABS
> Univ. of Wisc. - Madison
> scj at calshp.cals.wisc.edu

Scott,
   Heh, I had the same problem, and no one in my lab was able to make 1M
maleic at pH 7.5.  What we do is mix up a stock of 1M maleic.  The pH
turns out to be around 1.  We use this as a "stock" and make large
quantities of 1X maleic acid buffer by adding stock 5M NaCl, pH-ing and
then bringing up the volume to reach the appropriate concentrations.  Not
as nice as a 10X buffer, but not as frustrating as repeated failure.  I
have no idea how BM is able to make a 10X solution.

-- 
Rich Kernan
Dept of Microbiology 
University of GA