Figure 2. Effect of HIF-1α siRNA on HIF-1α protein expression. Cells were transfected with 15 and 25 nM HIF-1α siRNA and an siRNA non targeting control as indicated for 6 h. Twenty-four hours after transfection, cells were exposed to 4 h of hypoxia. Protein was collected immediately after treatment and blotted for HIF-1α. Bar graph represents the band intensity relative to the control. Error bars represent the standard error of the mean (n=3). β-actin is detected as loading control.