File:A-Novel-Chemotaxis-Assay-in-3-D-Collagen-Gels-by-Time-Lapse-Microscopy-pone.0052251.s001.ogv

English: Directional migration of freshly isolated human neutrophils in 3D collagen matrix towards Il-8. Images were taken at 10× magnification, and correspond to the Z projection of 5 layers reported at a reduced time and spatial resolution with about one frame every two minutes, in order to minimize the file dimension. The first 30 minutes, where each frame has a white overlay showing the progressive time and a dimension bar, are representative of the unstimulated condition where a limited fraction of cells move randomly. The IL-8 solution was added to the reservoir at t = 30 min. In the second part of the movie where the overlay is in black, cells are under the effect of an IL-8 concentration gradient. An increase in cell motility, that has been quantified in terms of average velocity and fraction of motile cells, and a preferential movement toward the source of the chemoattractant, i.e. towards the bottom part of the image, can be clearly noticed.