Can anybody help me with the phosphorylation of ErbB4 with Western blot. I used the p-ErbB4 antibody from santa cruz biotech but there were lots of nonspecific bands coming out. Is there any internalization of these receptors upon binding? i would like to ask whether we have to lyse the cells in 4 degrees to reduce this internalizaton? The bands are faint. So if I immunoprecipitate the ErbB4 , will the internalized receptor give signal? And if coimmunoprecipitated can i use any phospho tyrosine antibody (like pY20 or p-Tyr-100) for the band detection? I hope my question is clear. Thanks in advance.