Western blot analysis of Wehi cellsuntreated (H) and treated (T) with 25 μM Etoposidefor 4 hours at 37 °C. Cells were lysed in Tris-GlycineSDS sample buffer at the concentration of 1 x 107cells/ml, and 10 μl of clarified lysate were loadedper well of 4-20% Tris-Glycine gel. Proteins weretransferred onto an Immobilon FL membrane andribosylated proteins were detected using Trevigen'spolyclonal anti-PAR antibody (cat# 4336-APC-050)followed by an IR680-conjugated secondary antibody(Licor). The membrane was scanned using anOdyssey Infrared Imaging System (Licor).