Lane 1: HeLa cell lysate Lane 2: HeLa treated with 1μM staurosporine for 3 hours cell lysate Lane 3: Jurkat cell lysate Lane 4: Jurkat treated with 25μM Etoposide for 5 hours cell lysate Lane 5: MCF7 cell lysate (negative) Lane 6: HEK-293 cell lysate