Fig. 9. Defining the physical characteristics of biomolecular corona.
a A tomographic slice shows the BC surrounding the NPs (full series of 256 distinct cryo-EM images are provided in 10%Corona.rar and 50%Corona.rar files of the SI). The large circles represent spherical NPs. The BC is represented by black points forming clusters around the NPs. The horizontal black bar-like shapes in the bottom right corner of the image are artifacts of smaller gold NPs (used for focusing purposes) that are used to measure the scale of the image. b A binarized image showing the BC (white) surrounding the NP (blue). c The space around the NP is divided into spherical shells. The blue arrow points to the center of the cluster. The position of each cluster was determined according to where its center is located among the various shells. d A schematic representation of an arbitrary cluster. The size of the cluster was characterized by a sphere with a radius of gyration RG. Here we show a 2D representation. e The eigenvalues of the gyration tensor are represented with the radii of a hypothetical ellipsoid that best fits the cluster.