staining a chargeless protein

[Olin Anderson]

We are working with a 55 kDa polypeptide that has no charged amino acids.
Attempts to stain the polypeptide on PAGE gels has failed - tries
included commasie blue, amido black, silver, copper stain, Sypro, 
anilionaphthalene sulfonate, and fluorescein isothiocyanate.  The only
amino group is the N-terminal and it seems unreactive/blocked.  The
only amino acids in the polypeptide are P, G, Q, Y, T, and S.  Any
suggestions how to stain/detect this polypeptide in a gel?