Can be alkaline phosphatise inhibit by PBS? - (Jan/15/2010 )
I work with phosphor-specific antibodies as a control a use alkaline phosphatase. Phosphatase work well when I use them directly on the blot or cell lisate but do not work when I use then in IP. The mine different between IP and the cell lisates is that IP is washed with PBS and as a results complex protein-antibodies-proteinA is in PBS.
Do you know that PBS can inhibit alkaline phosphatise? It is possible?
yes. free phosphate will inhibit ap.
Use a tris- buffered wash instead of PBS.