Fig. 5. Three-dimensional 2-photon confocal laser scanning microscopy (2P-CLSM) of PHD1, PHD2, PHD3 and FIH-1. Different EGFP fluorescence intensities of single cells are visualized in false colors as indicated by the color bar. Up to 64 optical slices through transfected cells were recovered by 2P-CLSM. After reconstruction of the optical slices the distribution of the EGFP fluorescence within a single cell is 3D-visualized. A cut through the cell reveals the inside distribution. Overlays of all the optical slices are shown in the inserts (Metzen et al., 2003).