Imaging sections and whole cells with MIMS. (a-c) A 0.5-μm epon section of a mouse cochlea mounted on silicon. BM, basilar membrane; Cy, cytoplasm; IHC, inner hair cell; N, nucleus; St, stereocilia; TM, tectorial membrane. (a) Image obtained by reflection differential interference contrast microscopy (RDIC). Scale bar = 80 μm. The boxed area corresponds to the field analyzed with MIMS in (b). (b) MIMS analysis of the same section (80 μm across) at mass 12C14N; acquisition time 1 min. The boxed area corresponds to the field analyzed at higher resolution in (c). (c) A higher-magnification image of a 20-μm wide part of (b); acquisition time 10 min. (d) A mosaic image of a mouse cochlea, compiled from ten individual tiled 12C14N- mass images. BM, basilar membrane; HS, Hensen's stripe; IC, interdental cells; IHC, inner hair cell; ISC, inner sulcus cell; ISS, inner spiral sulcus; OHC, outer hair cells; PC, pillar cells; TC, tunnel of Corti; TM, tectorial membrane. Acquisition time 2 min per tile. (e) High spatial resolution mass image of stereocilia. BS, base of stereocilium; CP, cuticular plate; ES, an elongated structure that is not visible by optical or electron microscopy; PN, pericuticular necklace; S, stereocilium. Scale bar = 1 μm. Conditions of MIMS analysis: beam current 0.4 pA; beam diameter 100 nm; field 6 × 6 μm; 256 × 256 pixels; 18 msec/pixel. For further details see Additional data file 7. (f) Reference photomicrograph of a muscular artery from the rat stained with aldehyde-fuchsin. Original magnification 52× . (g-i) Contrast formation in an image of a mouse kidney artery. 12C14N- MIMS images at successively greater magnification, showing a brightly contrasting structure at the location of and with the appearance of the elastica interna. Image sizes: (g) 60 μm; (h) 30 μm; (i) 8 μm. Acquisition times: (g) 1 min; (h) 20 min; (i) 10 min. (j,k) Visualizing whole cells. (j) The surface of an untreated endothelial cell (72 μm × 28 μm, 10 min) and (k) endothelial cell after treatment with cytochalasin D (60 μm square, 10 min). L, lamellipodium; F, retraction fibers. Scale bars = (j,k) 10 μm.