Western blots of heat shock protein 90 (Hsp90) proteins from control and PRIMA-1-treated cells. Cells were treated with 100 μM PRIMA-1 for 2, 4 or 8 hours. 20 μg of protein samples of cell lysates from the whole cell extracts (WCE) and nuclear extracts (NE) of the control (C) and treated samples were separated by SDS-PAGE (4 to 20% polyacrylamide) and Western blotted with antibodies directed against both the α and β isoforms of Hsp90 (a) and against p53 (b). β-Actin was used as a loading control. The reactive bands were detected with the Odyssey™ Infrared Imaging System.