Do you have any recommendations for using the PosphoProtein Kit with starting material other than cells?
FAQ ID -597

Customers report good results when achieving efficient lysis of their starting material using their home-made lysis buffers, and subsequently dialysing their lysate against the PhosphoProtein Lysis Buffer provided in the PhosphoProtein Purification Kit . Complete exchange of the home-made lysis buffer with the PhosphoProtein Lysis buffer is crucial. The PhosphoProtein Lysis buffer is specifically formulated to bind phosphorylated protein to the column, and is absolutely essential for the procedure.