Figure 1

Western blot analysis on expression levels of EGFR/HER1 and HER2 in five breast cancer cell lines tested. The harvested cells were lysed, and the lysate was subjected to electrophoresis on polyacrylamide gel. The protein was transferred to nitrocellulose membranes and immunoblotted with appropriate primary antibodies. For detection, the blots were incubated with the appropriate secondary antibodies conjugated with horseradish peroxidase, and developed using ECL Plus Western Blotting Detection Reagents. Actin was used as the internal control.