Fig. 2. The PTEN-GFP chimera does not polarize during chemotaxis. (A) In chemotaxis assays, a passive fMLP diffusion gradient was established near HL60 cells co-expressing PTEN-GFP and RFP. Dark-phase and red and green fluorescence were recorded in a confocal microscope; the first 20 frames were recorded at 5-second intervals and remaining frames every 20 seconds. Dark-phase, green fluorescence, and red and green merge are shown; a video with single-color recording is provided (see supplementary material, Movie 1). Asterisk indicates pipette tip. The cell is representative of 28 out of 30 cells analysed. Bar, 10 µm. (B) Red and green fluorescence scanning using line `a' of cells in A. (C) Red and green fluorescence scanning using line `b' of cells in A. (D) HL60 cells co-expressing PTEN-GFP and RFP-GPI were analyzed in chemotaxis assays towards fMLP as in A. Dark-phase, green fluorescence, and red and green channel merge are shown; see supplementary material Movie 2. Dark-phase images are shown at a lower magnification to indicate the position of the chemoattractant source. The cell is representative of 25 out of 25 cells analysed. Bar, 10 µm. (E) Red and green fluorescence scanning of cells in panel D.