کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5913667 1162697 2015 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Three-dimensional mass density mapping of cellular ultrastructure by ptychographic X-ray nanotomography
ترجمه فارسی عنوان
نقشه برداری چگالی توده سه بعدی در زیر ساخت های سلولی با استفاده از نانوتیموگرافی اشعه ایکس پتیکوگرافی
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شناسی مولکولی
چکیده انگلیسی

We demonstrate absolute quantitative mass density mapping in three dimensions of frozen-hydrated biological matter with an isotropic resolution of 180 nm. As model for a biological system we use Chlamydomonas cells in buffer solution confined in a microcapillary. We use ptychographic X-ray computed tomography to image the entire specimen, including the 18 μm-diameter capillary, thereby providing directly an absolute mass density measurement of biological matter with an uncertainty of about 6%. The resulting maps have sufficient contrast to distinguish cells from the surrounding ice and several organelles of different densities inside the cells. Organelles are identified by comparison with a stained, resin-embedded specimen, which can be compared with established transmission electron microscopy results. For some identified organelles, the knowledge of their elemental composition reduces the uncertainty of their mass density measurement down to 1% with values consistent with previous measurements of dry weight concentrations in thin cellular sections by scanning transmission electron microscopy. With prospects of improving the spatial resolution in the near future, we expect that the capability of non-destructive three-dimensional mapping of mass density in biological samples close to their native state becomes a valuable method for measuring the packing of organic matter on the nanoscale.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Biology - Volume 192, Issue 3, December 2015, Pages 461-469
نویسندگان
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