Detection of apoptosis by flow cytometry: graphical format. Cells were treated and stained as described for Fig. 7. Shown is a graphical representation of this data with statistical analysis from a representative of 5 independent experiments. $, P < 0.05 compared to normoxic mock transfected and HIF-1α siRNA; *, P < 0.05 compared to hypoxic HIF-1α siRNA and HIF-1α expression vector with HEPES; #, P < 0.05 compared to hypoxic HIF-1α expression vector with or without 2-DG. siRNA: A549 cells transfected HIF-1α siRNA vector, Mock: mock-transfected, HIF: A549 cells transfected with HIF-1α expression plasmid, HIF+2-DG: Cells transfected with HIF-1α expression plasmid and cultured with 2-DG, HIF+HEPES: Cells transfected with HIF-1α expression plasmid and cultured with medium containing HEPES.