Observational study to visualize and confirm that actin filament labeling using Phalloidin could enhance identification of endothelial tip cells forming new vessel structures in differentiating mouse embryonic stem cells.

Observational study to visualize and confirm that actin filament labeling using Phalloidin (red) could enhance identification of endothelial tip cells forming new vessel structures in differentiating mouse embryonic stem cells harboring enhanced Green Fluorescent Protein (eGFP) expression under control of the Flk-1/Kdr promoter (i.e. Flk1:eGFP, green). Cell nuclei are labeled by DAPI (blue in the Merge image). Images acquired on a Leica SP8 point-scanning confocal microscope to detect actin filaments in a sprouting endothelial cell within an angiogenic vessel. Volumetric images taken through the z-axis were acquired at 40x. Images in the figure are compressed z-stacks within a selected range, but the raw image files in .lif format are also included.