Serial Thick Section Gas Cluster Ion Beam Scanning Electron Microscopy (original) (raw)

Combining serial block face and focused ion beam scanning electron microscopy for 3D studies of rare events

Methods in Cell Biology, 2019

Volume electron microscopy allows for the automated acquisition of serial-section imaging data that can be reconstructed in three-dimensions (3D) to provide a detailed, geometrically accurate view of cellular ultrastructure. Two, volume electron microscopy (EM) techniques, serial block face scanning electron microscopy (SBF-SEM) and focused ion beam scanning electron microscopy (FIB-SEM), use a similar slice-and-view approach but differ in their fields of view and 3D resolution. This chapter highlights a workflow where the ability of SBF-SEM to image a large field of view is combined with the precise sectioning capability of FIB-SEM to first locate a rare cellular event in a large tissue volume and then inspect the event with higher resolution. Using these two EM platforms in synergy is a powerful technique and can be useful for both simple structural studies as well as correlative studies using both light and electron microscopy.

GCIB-SEM: A path to 10 nm isotropic imaging of cubic millimeter volumes

2019

Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) generates 3D datasets optimally suited for segmentation of cell ultrastructure and automated connectome tracing but is limited to small fields of view and is therefore incompatible with the new generation of ultrafast multibeam SEMs. In contrast, section-based techniques are multibeam-compatible but are limited in z-resolution making automatic segmentation of cellular ultrastructure difficult. Here we demonstrate a novel 3D electron microscopy technique, Gas Cluster Ion Beam SEM (GCIB-SEM), in which top-down, wide-area ion milling is performed on a series of thick sections, acquiring < 10 nm isotropic datasets of each which are then stitched together to span the full sectioned volume. Based on our results, incorporating GCIB-SEM into existing single beam and multibeam SEM workflows should be straightforward and should dramatically increase reliability while simultaneously improving z-resolution by a factor of 3 or more.

A New Approach to Studying Biological and Soft Materials Using Focused Ion Beam Scanning Electron Microscopy (FIB SEM)

Journal of Physics: Conference Series, 2006

Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combination of sample preparation techniques and transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). Scanning electron microscopy (SEM) is well known for the determination of surface characteristics and morphology. However, the desire to understand the three dimensional relationships of meso-scale hierarchies has led to the development of advanced microscopy techniques, to give a further complementary approach. A focused ion beam (FIB) can be used as a nano-scalpel and hence allows us to reveal internal microstructure in a site-specific manner. Whilst FIB instruments have been used to study and verify the three-dimensional architecture of man made materials, SEM and FIB technologies have now been brought together in a single instrument representing a powerful combination for the study of biological specimens and soft materials. We demonstrate the use of FIB SEM to study three-dimensional relationships for a range of length scales and materials, from small-scale cellular structures to the larger scale interactions between biomedical materials and tissues. FIB cutting of heterogeneous mixtures of hard and soft materials, resulting in a uniform cross-section, has proved to be of particular value since classical preparation methods tend to introduce artefacts. Furthermore, by appropriate selection, we can sequentially cross-section to create a series of 'slices' at specific intervals. 3D reconstruction software can then be used to volume-render information from the 2D slices, enabling us to immediately see the spatial relationships between microstructural components.

Oxygen plasma focused ion beam scanning electron microscopy for biological samples

Over the past decade, gallium Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) has been established as a key technology for cellular tomography. The utility of this approach, however, is severely limited both by throughput and the limited selection of compatible sample preparation protocols. Here, we address these limitations and present oxygen plasma FIB (O-PFIB) as a new and versatile tool for cellular FIB-SEM tomography. Oxygen displays superior resin compatibility to other ion beams and produces curtain-free surfaces with minimal polishing. Our novel approach permits more flexible sample preparation and 30% faster data collection when compared to using gallium ion sources. We demonstrate this alternative FIB is applicable to a variety of embedding procedures and biological samples including brain tissue and whole organisms. Finally, we demonstrate the use of O-PFIB to produce targeted FIB-SEM tomograms through fiducial free en-block correlative light and electron microscopy.

Specific site cross-sectional sample preparation using focused ion beam for transmission electron microscopy

Progress in Crystal Growth and Characterization of Materials, 1998

Sample preparation using focused ion beam (FIB) for transmission Electron Microscopy (TEM) analysis was reviewed. Improving the quality of FIB prepared TEM sample has been an issue in the past. A specific site cross-sectional sample preparation method has been developed using FIB milling for TEM characterization of integrated circuits (ICs). Approach of front side and back side milling has been applied to thin the semiconductor samples for electron transparency. Back side milling has been applied for the first time in our TEM sample preparation using FIB milling. Proper tilting of the stage and use of low beam current are found to be critical for TEM samples quality. Samples prepared during present work are thinner, artifact-free, and of excellent quality for TEM analysis. It is possible to prepare specific site cross-sectional TEM samples of ICs within 2-3 hours using FIB milling. Some examples of specific site cross-sectional TEM analysis of Si based device structures are presented. Final achievable thicknesses of the samples are exemplified from the fact that atomic resolution imaging was possible and microstructure was seen in the tungsten plugs.

Multi-resolution correlative focused ion beam scanning electron microscopy: Applications to cell biology

Journal of Structural Biology, 2014

Efficient correlative imaging of small targets within large fields is a central problem in cell biology. Here, we demonstrate a series of technical advances in focused ion beam scanning electron microscopy (FIB-SEM) to address this issue. We report increases in the speed, robustness and automation of the process, and achieve consistent z slice thickness of $3 nm. We introduce ''keyframe imaging'' as a new approach to simultaneously image large fields of view and obtain high-resolution 3D images of targeted sub-volumes. We demonstrate application of these advances to image post-fusion cytoplasmic intermediates of the HIV core. Using fluorescently labeled cell membranes, proteins and HIV cores, we first produce a ''target map'' of an HIV infected cell by fluorescence microscopy. We then generate a correlated 3D EM volume of the entire cell as well as high-resolution 3D images of individual HIV cores, achieving correlative imaging across a volume scale of 10 9 in a single automated experimental run.

Surface damage induced by FIB milling and imaging of biological samples is controllable

Microscopy Research and Technique, 2007

Focused ion beam (FIB) techniques are among the most important tools for the nanostructuring of surfaces. We used the FIB/SEM (scanning electron microscope) for milling and imaging of digestive gland cells. The aim of our study was to document the interactions of FIB with the surface of the biological sample during FIB investigation, to identify the classes of artifacts, and to test procedures that could induce the quality of FIB milled sections by reducing the artifacts. The digestive gland cells were prepared for conventional SEM. During FIB/SEM operation we induced and enhanced artifacts. The results show that FIB operation on biological tissue affected the area of the sample where ion beam was rastering. We describe the FIB-induced surface major artifacts as a melting-like effect, sweating-like effect, morphological deformations, and gallium (Ga +) implantation. The FIB induced surface artifacts caused by incident Ga + ions were reduced by the application of a protective platinum strip on the surface exposed to the beam and by a suitable selection of operation protocol. We recommend the same sample preparation methods, FIB protocol for milling and imaging to be used also for other biological samples.

Enhanced FIB-SEM systems for large-volume 3D imaging

eLife, 2017

Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) can automatically generate 3D images with superior z-axis resolution, yielding data that needs minimal image registration and related post-processing. Obstacles blocking wider adoption of FIB-SEM include slow imaging speed and lack of long-term system stability, which caps the maximum possible acquisition volume. Here we present techniques that accelerate image acquisition while greatly improving FIB-SEM reliability, allowing the system to operate for months and generating continuously imaged volumes > 10(6) µm(3). These volumes are large enough for connectomics, where the excellent z resolution can help in tracing of small neuronal processes and accelerate the tedious and time-consuming human proofreading effort. Even higher resolution can be achieved on smaller volumes. We present example data sets from mammalian neural tissue, Drosophila brain, and Chlamydomonas reinhardtii to illustrate the power of this novel high-resol...

Focused ion beam (FIB)/scanning electron microscopy (SEM) in tissue structural research

Protoplasma, 2010

The focused ion beam (FIB) and scanning electron microscope (SEM) are commonly used in material sciences for imaging and analysis of materials. Over the last decade, the combined FIB/SEM system has proven to be also applicable in the life sciences. We have examined the potential of the focused ion beam/scanning electron microscope system for the investigation of biological tissues of the model organism Porcellio scaber (Crustacea: Isopoda). Tissue from digestive glands was prepared as for conventional SEM or as for transmission electron microscopy (TEM). The samples were transferred into FIB/SEM for FIB milling and an imaging operation. FIB-milled regions were secondary electron imaged, back-scattered electron imaged, or energy dispersive X-ray (EDX) analyzed. Our results demonstrated that FIB/SEM enables simultaneous investigation of sample gross morphology, cell surface characteristics, and subsurface structures. The same FIB-exposed regions were analyzed by EDX to provide basic compositional data. When samples were prepared as for TEM, the information obtained with FIB/SEM is comparable, though at limited magnification, to that obtained from TEM. A combination of imaging, micro-manipulation, and compositional analysis appears of particular interest in the investigation of epithelial tissues, which are subjected to various endogenous and exogenous conditions affecting their structure and function. The FIB/SEM is a promising tool for an overall examination of epithelial tissue under normal, stressed, or pathological conditions.

A review of focused ion beam milling techniques for TEM specimen preparation

Micron, 1999

The use of focused ion beam (FIB) milling for the preparation of transmission electron microscopy (TEM) specimens is described. The operation of the FIB instrument is discussed and the conventional and lift-out techniques for TEM specimen preparation and the advantages and disadvantages of each technique are detailed. The FIB instrument may be used for rapid site-specific preparation of both cross-section and plan view TEM specimens. ᭧ PERGAMON 0968-4328/99/$ -see front matter ᭧