Prestaining Proteins

[Richard Near]

I am interested in prestaining some proteins to
serve as markers in sds gels and/or chromatography.
I realize that this will affect the apparent Mwt, bu
t, for my crude applications (at least for now), it will
serve it's purpose.  MY Question: does anyone have a 
simple protocol for prelableling proteins that should
be stable in sds and/or urea.

Thanks
Rick
rocket1 at bu.edu