I have used casein for many years with good effect. You need to make a
saturated solution (2% w/v) which is a bit of a fiddle but that will
keep for several weeks. You can then try different dilutions to find
which works best (normally between 0.5 and 1% casein). I also use it in
all washes and in the secondary antibody step. You could try TWEEN
detergent but some studies say that it can alter the immunogenicity of
some proteins.
Simon Worrall Ph.D.
Dept of Biochemistry and Molecular Biology
University of Queensland
