LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 151

Search options

  1. Article ; Online: Quantification of gallium cryo-FIB milling damage in biological lamellae.

    Lucas, Bronwyn A / Grigorieff, Nikolaus

    Proceedings of the National Academy of Sciences of the United States of America

    2023  Volume 120, Issue 23, Page(s) e2301852120

    Abstract: Cryogenic electron microscopy (cryo-EM) can reveal the molecular details of biological processes in their native, cellular environment at atomic resolution. However, few cells are sufficiently thin to permit imaging with cryo-EM. Thinning of frozen cells ...

    Abstract Cryogenic electron microscopy (cryo-EM) can reveal the molecular details of biological processes in their native, cellular environment at atomic resolution. However, few cells are sufficiently thin to permit imaging with cryo-EM. Thinning of frozen cells to <500 nm lamellae by focused-ion-beam (FIB) milling has enabled visualization of cellular structures with cryo-EM. FIB milling represents a significant advance over prior approaches because of its ease of use, scalability, and lack of large-scale sample distortions. However, the amount of damage it causes to a thinned cell section has not yet been determined. We recently described an approach for detecting and identifying single molecules in cryo-EM images of cells using 2D template matching (2DTM). 2DTM is sensitive to small differences between a molecular model (template) and the detected structure (target). Here, we use 2DTM to demonstrate that under the standard conditions used for machining lamellae of biological samples, FIB milling introduces a layer of variable damage that extends to a depth of 60 nm from each lamella surface. This layer of damage limits the recovery of information for in situ structural biology. We find that the mechanism of FIB milling damage is distinct from radiation damage during cryo-EM imaging. By accounting for both electron scattering and FIB milling damage, we estimate that FIB milling damage with current protocols will negate the potential improvements from lamella thinning beyond 90 nm.
    MeSH term(s) Gallium ; Microscopy, Electron ; Freezing ; Electrons ; Cryoelectron Microscopy/methods ; Electron Microscope Tomography/methods
    Chemical Substances Gallium (CH46OC8YV4)
    Language English
    Publishing date 2023-05-22
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2301852120
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Exploring the Limits of 2D Template Matching for Detecting Targets in Cellular Cryo-EM Images.

    Zhang, Kexin / Lucas, Bronwyn / Grigorieff, Nikolaus

    Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada

    2023  Volume 29, Issue 29 Suppl 1, Page(s) 931

    Language English
    Publishing date 2023-08-23
    Publishing country England
    Document type Journal Article
    ZDB-ID 1385710-1
    ISSN 1435-8115 ; 1431-9276
    ISSN (online) 1435-8115
    ISSN 1431-9276
    DOI 10.1093/micmic/ozad067.462
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Baited reconstruction with 2D template matching for high-resolution structure determination in vitro and in vivo without template bias.

    Lucas, Bronwyn A / Himes, Benjamin A / Grigorieff, Nikolaus

    eLife

    2023  Volume 12

    Abstract: Previously we showed that 2D template matching (2DTM) can be used to localize macromolecular complexes in images recorded by cryogenic electron microscopy (cryo-EM) with high precision, even in the presence of noise and cellular background (Lucas et al., ...

    Abstract Previously we showed that 2D template matching (2DTM) can be used to localize macromolecular complexes in images recorded by cryogenic electron microscopy (cryo-EM) with high precision, even in the presence of noise and cellular background (Lucas et al., 2021; Lucas et al., 2022). Here, we show that once localized, these particles may be averaged together to generate high-resolution 3D reconstructions. However, regions included in the template may suffer from template bias, leading to inflated resolution estimates and making the interpretation of high-resolution features unreliable. We evaluate conditions that minimize template bias while retaining the benefits of high-precision localization, and we show that molecular features
    MeSH term(s) Cryoelectron Microscopy/methods ; Ribosomes/chemistry ; Macromolecular Substances/chemistry ; Image Processing, Computer-Assisted/methods
    Chemical Substances Macromolecular Substances
    Language English
    Publishing date 2023-11-27
    Publishing country England
    Document type Journal Article
    ZDB-ID 2687154-3
    ISSN 2050-084X ; 2050-084X
    ISSN (online) 2050-084X
    ISSN 2050-084X
    DOI 10.7554/eLife.90486
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: Cryo-TEM simulations of amorphous radiation-sensitive samples using multislice wave propagation.

    Himes, Benjamin / Grigorieff, Nikolaus

    IUCrJ

    2021  Volume 8, Issue Pt 6, Page(s) 943–953

    Abstract: Image simulation plays a central role in the development and practice of high-resolution electron microscopy, including transmission electron microscopy of frozen-hydrated specimens (cryo-EM). Simulating images with contrast that matches the contrast ... ...

    Abstract Image simulation plays a central role in the development and practice of high-resolution electron microscopy, including transmission electron microscopy of frozen-hydrated specimens (cryo-EM). Simulating images with contrast that matches the contrast observed in experimental images remains challenging, especially for amorphous samples. Current state-of-the-art simulators apply
    Language English
    Publishing date 2021-09-30
    Publishing country England
    Document type Journal Article
    ZDB-ID 2754953-7
    ISSN 2052-2525
    ISSN 2052-2525
    DOI 10.1107/S2052252521008538
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Cryo-TEM simulations of amorphous radiation-sensitive samples using multislice wave propagation

    Benjamin Himes / Nikolaus Grigorieff

    IUCrJ, Vol 8, Iss 6, Pp 943-

    2021  Volume 953

    Abstract: Image simulation plays a central role in the development and practice of high-resolution electron microscopy, including transmission electron microscopy of frozen-hydrated specimens (cryo-EM). Simulating images with contrast that matches the contrast ... ...

    Abstract Image simulation plays a central role in the development and practice of high-resolution electron microscopy, including transmission electron microscopy of frozen-hydrated specimens (cryo-EM). Simulating images with contrast that matches the contrast observed in experimental images remains challenging, especially for amorphous samples. Current state-of-the-art simulators apply post hoc scaling to approximate empirical solvent contrast, attenuated image intensity due to specimen thickness and amplitude contrast. This practice fails for images that require spatially variable scaling, e.g. simulations of a crowded or cellular environment. Modeling both the signal and the noise accurately is necessary to simulate images of biological specimens with contrast that is correct on an absolute scale. The `frozen plasmon' method is introduced to explicitly model spatially variable inelastic scattering processes in cryo-EM specimens. This approach produces amplitude contrast that depends on the atomic composition of the specimen, reproduces the total inelastic mean free path as observed experimentally and allows for the incorporation of radiation damage in the simulation. These improvements are quantified using the matched filter concept to compare simulation and experiment. The frozen plasmon method, in combination with a new mathematical formulation for accurately sampling the tabulated atomic scattering potentials onto a Cartesian grid, is implemented in the open-source software package cisTEM.
    Keywords cryo-tem ; multislice wave propagation ; cistem ; frozen plasmon method ; Science ; Q
    Subject code 535
    Language English
    Publishing date 2021-11-01T00:00:00Z
    Publisher International Union of Crystallography
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  6. Article ; Online: In situ single particle classification reveals distinct 60S maturation intermediates in cells.

    Lucas, Bronwyn A / Zhang, Kexin / Loerch, Sarah / Grigorieff, Nikolaus

    eLife

    2022  Volume 11

    Abstract: Previously, we showed that high-resolution template matching can localize ribosomes in two-dimensional electron cryo-microscopy (cryo-EM) images of ... ...

    Abstract Previously, we showed that high-resolution template matching can localize ribosomes in two-dimensional electron cryo-microscopy (cryo-EM) images of untilted
    MeSH term(s) Cryoelectron Microscopy/methods ; Likelihood Functions ; Models, Molecular ; Ribosomes ; Saccharomyces cerevisiae ; Saccharomyces cerevisiae Proteins
    Chemical Substances Saccharomyces cerevisiae Proteins
    Language English
    Publishing date 2022-08-25
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2687154-3
    ISSN 2050-084X ; 2050-084X
    ISSN (online) 2050-084X
    ISSN 2050-084X
    DOI 10.7554/eLife.79272
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Defocus Corrected Large Area Cryo-EM (DeCo-LACE) for label-free detection of molecules across entire cell sections.

    Elferich, Johannes / Schiroli, Giulia / Scadden, David T / Grigorieff, Nikolaus

    eLife

    2022  Volume 11

    Abstract: A major goal of biological imaging is localization of biomolecules inside a cell. Fluorescence microscopy can localize biomolecules inside whole cells and tissues, but its ability to count biomolecules and accuracy of the spatial coordinates is limited ... ...

    Abstract A major goal of biological imaging is localization of biomolecules inside a cell. Fluorescence microscopy can localize biomolecules inside whole cells and tissues, but its ability to count biomolecules and accuracy of the spatial coordinates is limited by the wavelength of visible light. Cryo-electron microscopy (cryo-EM) provides highly accurate position and orientation information of biomolecules but is often confined to small fields of view inside a cell, limiting biological context. In this study, we use a new data-acquisition scheme called Defocus-Corrected Large-Area cryo-EM (DeCo-LACE) to collect high-resolution images of entire sections (100- to 250-nm-thick lamellae) of neutrophil-like mouse cells, representing 1-2% of the total cellular volume. We use 2D template matching (2DTM) to determine localization and orientation of the large ribosomal subunit in these sections. These data provide maps of ribosomes across entire sections of mammalian cells. This high-throughput cryo-EM data collection approach together with 2DTM will advance visual proteomics and provide biological insight that cannot be obtained by other methods.
    MeSH term(s) Animals ; Mice ; Cryoelectron Microscopy/methods ; Microscopy, Fluorescence/methods ; Ribosomes ; Mammals
    Language English
    Publishing date 2022-11-16
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural
    ZDB-ID 2687154-3
    ISSN 2050-084X ; 2050-084X
    ISSN (online) 2050-084X
    ISSN 2050-084X
    DOI 10.7554/eLife.80980
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article: Direct detection pays off for electron cryo-microscopy.

    Grigorieff, Nikolaus

    eLife

    2013  Volume 2, Page(s) e00573

    Abstract: Improved electron detectors and image-processing techniques will allow the structures of macromolecules to be determined from tens of thousands of single-particle cryo-EM images, rather than the hundreds of thousands needed previously. ...

    Abstract Improved electron detectors and image-processing techniques will allow the structures of macromolecules to be determined from tens of thousands of single-particle cryo-EM images, rather than the hundreds of thousands needed previously.
    MeSH term(s) Cryoelectron Microscopy/methods ; Image Processing, Computer-Assisted
    Language English
    Publishing date 2013-02-19
    Publishing country England
    Document type Journal Article
    ZDB-ID 2687154-3
    ISSN 2050-084X
    ISSN 2050-084X
    DOI 10.7554/eLife.00573
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Defocus Corrected Large Area Cryo-EM (DeCo-LACE) for label-free detection of molecules across entire cell sections

    Johannes Elferich / Giulia Schiroli / David T Scadden / Nikolaus Grigorieff

    eLife, Vol

    2022  Volume 11

    Abstract: A major goal of biological imaging is localization of biomolecules inside a cell. Fluorescence microscopy can localize biomolecules inside whole cells and tissues, but its ability to count biomolecules and accuracy of the spatial coordinates is limited ... ...

    Abstract A major goal of biological imaging is localization of biomolecules inside a cell. Fluorescence microscopy can localize biomolecules inside whole cells and tissues, but its ability to count biomolecules and accuracy of the spatial coordinates is limited by the wavelength of visible light. Cryo-electron microscopy (cryo-EM) provides highly accurate position and orientation information of biomolecules but is often confined to small fields of view inside a cell, limiting biological context. In this study, we use a new data-acquisition scheme called Defocus-Corrected Large-Area cryo-EM (DeCo-LACE) to collect high-resolution images of entire sections (100- to 250-nm-thick lamellae) of neutrophil-like mouse cells, representing 1–2% of the total cellular volume. We use 2D template matching (2DTM) to determine localization and orientation of the large ribosomal subunit in these sections. These data provide maps of ribosomes across entire sections of mammalian cells. This high-throughput cryo-EM data collection approach together with 2DTM will advance visual proteomics and provide biological insight that cannot be obtained by other methods.
    Keywords cryo-EM ; ribosome ; neutrophil ; Medicine ; R ; Science ; Q ; Biology (General) ; QH301-705.5
    Subject code 500
    Language English
    Publishing date 2022-11-01T00:00:00Z
    Publisher eLife Sciences Publications Ltd
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  10. Article ; Online: In situ single particle classification reveals distinct 60S maturation intermediates in cells

    Bronwyn A Lucas / Kexin Zhang / Sarah Loerch / Nikolaus Grigorieff

    eLife, Vol

    2022  Volume 11

    Abstract: Previously, we showed that high-resolution template matching can localize ribosomes in two-dimensional electron cryo-microscopy (cryo-EM) images of untilted Mycoplasma pneumoniae cells with high precision (Lucas et al., 2021). Here, we show that ... ...

    Abstract Previously, we showed that high-resolution template matching can localize ribosomes in two-dimensional electron cryo-microscopy (cryo-EM) images of untilted Mycoplasma pneumoniae cells with high precision (Lucas et al., 2021). Here, we show that comparing the signal-to-noise ratio (SNR) observed with 2DTM using different templates relative to the same cellular target can correct for local variation in noise and differentiate related complexes in focused ion beam (FIB)-milled cell sections. We use a maximum likelihood approach to define the probability of each particle belonging to each class, thereby establishing a statistic to describe the confidence of our classification. We apply this method in two contexts to locate and classify related intermediate states of 60S ribosome biogenesis in the Saccharomyces cerevisiae cell nucleus. In the first, we separate the nuclear pre-60S population from the cytoplasmic mature 60S population, using the subcellular localization to validate assignment. In the second, we show that relative 2DTM SNRs can be used to separate mixed populations of nuclear pre-60S that are not visually separable. 2DTM can distinguish related molecular populations without the need to generate 3D reconstructions from the data to be classified, permitting classification even when only a few target particles exist in a cell.
    Keywords ribosome biogenesis ; in situ cryo-EM ; 2DTM ; particle classification ; nucleus ; FIB-milling ; Medicine ; R ; Science ; Q ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2022-08-01T00:00:00Z
    Publisher eLife Sciences Publications Ltd
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

To top