Figure 4. Electron tomography reveals membranes within the internal core of eosinophil LBs.

(A–F) A gallery of 4 nm digital, serial slices of a tomogram taken from a representative human eosinophil stimulated with eotaxin-1. An eosinophil-specific granule is indicated (*). LB boundaries and internal membranes in consecutive tomogram slices were manually contoured in yellow and blue, respectively (as in Fii), and a computer-based 3D model is shown (G and H). LB membranes are seen as interconnected tubules (H). Virtual slices were extracted from 3D reconstructions of a 400-nm eosinophil plastic section, analyzed by fully automated electron tomography at 200 kV. Original scale bars, 500 nm (A–Fi); 400 nm (Fii); 300 nm (G and H). Reprinted from ref. [11], with permission.