I've used 2 M KCl and 3 M NaCl without any trouble. Notably, you can use
urea as well for denatured proteins. I've purified histones on HisSELECT w/o
any trouble and they have a pI of 11. Naturally, His-tag is a bit of an
overkill for histones and such since they're purifiable over CM columns at
Dear CCP4BBers,
One of those questions regarding purification rather than
crystallography:
Reading the Qiagen manual for the Ni-NTA matrices, in the table of
compatibility of reagents with Ni-NTA matrices, SDS is mentioned
(only together with sarkosyl) as Not recommended, but up to 0.3%
Ni salt of dodecyl sulphate is not soluble. Therefore (at least in theory)
SDS may leach the Ni out of the chelate and deposit it throughout the column
in baby-blue soapy flecks. Having said that, I must add that if you have to
use more than 0.1% SDS then you're dealing with a truly extreme case!
