Figure 7.

3D-PART measurement of a single virus landing on the membrane of a HuH7 cell. The transparent ellipse is a guide to the eye and is generated by fitting an ellipse to the 2D optical image of the cell and extending in Z to the virus-like particle binding event. The different colors represent elapsed time, as indicated by the colorbar, with the binding event occurring at the end of the trajectory (red). The virus diffuses in 3D with a curved excluded volume, indicating close approach to the cell surface before the actual binding event.