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Focused ion beam milling of vitreous water: prospects for an alternative to cryo‐ultramicrotomy of frozen‐hydrated biological samples
Author(s) -
MARKO M.,
HSIEH C.,
MOBERLYCHAN W.,
MANNELLA C. A.,
FRANK J.
Publication year - 2006
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.2006.01567.x
Subject(s) - devitrification , focused ion beam , materials science , transmission electron microscopy , ion beam , ion , nanotechnology , beam (structure) , analytical chemistry (journal) , optics , chemical engineering , chemistry , crystallization , chromatography , physics , organic chemistry , engineering
Summary The feasibility of using a focused ion beam (FIB) for the purpose of thinning vitreously frozen biological specimens for transmission electron microscopy (TEM) was explored. A concern was whether heat transfer beyond the direct ion interaction layer might devitrify the ice. To test this possibility, we milled vitreously frozen water on a standard TEM grid with a 30‐keV Ga + beam, and cryo‐transferred the grid to a TEM for examination. Following FIB milling of the vitreous ice from a thickness of approximately 1200 nm to 200–150 nm, changes characteristic of heat‐induced devitrification were not observed by TEM, in either images or diffraction patterns. Although numerous technical challenges remain, it is anticipated that ‘cryo‐FIB thinning’ of bulk frozen‐hydratred material will be capable of producing specimens for TEM cryo‐tomography with much greater efficiency than cryo‐ultramicrotomy, and without the specimen distortions and handling difficulties of the latter.