Western-blots
Cells, untreated or treated for 24 h with 0.5 μg/ml adriamycin, were lysed on the dish in a buffer consisting of 50 mM Tris (pH 8.0), 5 mM EDTA, 150 mM NaCl, 0.5% Nonidet P-40, 1 mM PMSF, 1 mM sodium vanadate, 10 mM NaF and Complete Mini Protease Inhibitors (Roche Diagnostics) at 4°C for 30 min. Lysates were scraped, then spun at 6000× g at 4°C for 10 min. Protein concentration in the supernatant was determined using the Bio-Rad DC protein assay. Lysates were separated on single percentage SDS/PAGE gels, then electrophoretically transferred to poly(vinylidene difluoride), using standard procedures.Blots were incubated in 5% non-fat dried milk in TBST (0.02 M Tris, pH 7.6/0.35 M NaCl/0.1% Tween-20) for 1 h at room temperature before probing with primary antibodies against p53 (CM-5, Novacastra) and -actin (Sigma). Secondary antibodies used include peroxidase-conjugated goat anti-mouse IgG and anti-rabbit IgG (Pierce). Probed blots were incubated with Pierce Supersignal West Pico chemiluminescent substrate and exposed to X-ray films.