Figure 4.

Human HT 1080 fibrosarcoma cells, wild type or transfected with the hypoxia-responsive 5HRE-hCMVmp-d2EGFP vector or the positive control CMV-d2EGFP vector under aerobic (20% oxygen) or hypoxic (<0.02% oxygen for 12 hours) conditions. EGFP fluorescence versus streptavidin-PE fluorescence after labeling with ELK3-51 biotin, an antibody against the hypoxic marker EF5. Cells were processed for EF5 detection immediately after hypoxic treatment. The populations were gated for scatter, and electronic compensation was applied. The data are from a representative experiment.