Can anyone help me? I am running some experiments looking at the ribosomal protein S6 and quantitating both the total and phosphorylated levels in several different tissues. So far everything has worked out well and we are getting nice bands at the appropriate size (32kDa) in mouse adult liver tissue and in placental, yolk sac and embryonic tissue. However, when we look in fetal liver tissue we see very strong bands at 16kDa and only a tiny weak band at 32 kDa. We have done the appropriate controls and so we know the antibodies are behaving properly. What are these lighter bands and why do we only see them in fetal liver? We are using the Cell Signalling antibodies and the phospho one targets Ser235/236.
Any ideas any one?