Gene mapping on human metaphase chromosomes by in situ hybridization with 3H, 35S, and 32P labeled probes and transmission electron microscopy

Chromosoma ◽  
1986 ◽  
Vol 93 (4) ◽  
pp. 305-312 ◽  
Author(s):  
Chang-ben Li ◽  
Madeline Wu ◽  
Irene S. Margitich ◽  
Norman Davidson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
In Situ Hybridization ◽  
Gene Mapping ◽  
Metaphase Chromosomes ◽  
Transmission Electron

scholarly journals Monitoring morphology and signal during non-radioactive in situ hybridization procedures by reflection-contrast microscopy and transmission electron microscopy.

1995 ◽  
Vol 43 (7) ◽  
pp. 665-674 ◽  
Author(s):  
M V Macville ◽  
A G Van Dorp ◽  
K C Wiesmeijer ◽  
R W Dirks ◽  
J A Fransen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
In Situ Hybridization ◽  
Messenger Rna ◽  
Detection Efficiency ◽  
Rna Detection ◽  
Ultrastructural Morphology ◽  
Transmission Electron ◽  
Contrast Microscopy

We analyzed the effects of steps in RNA in situ hybridization (ISH) procedures on morphology and hybridization signal with reflection-contrast microscopy (RCM) and transmission electron microscopy (TEM). In chessboard experiments, a range of fixatives containing formaldehyde, glutaraldehyde, or both, and various permeabilization protocols, including ethanol and pepsin treatment, were investigated. A transfected rat fibroblast cell line that harbors an inducible human cytomegalovirus immediate early (IE) transcription unit, and specific probes for 28S ribosomal RNA and IE messenger RNA were used for this purpose. Probes were labeled with digoxigenin and hybrids were detected with anti-digoxigenin F(ab)2 fragments conjugated to horseradish peroxidase, followed by diaminobenzidine/H2O2 reaction. Effects of fixation and pre-treatments on RNA detection efficiency and morphology were monitored by RCM on whole cells. After Epon embedding and ultra-thin cross-sectioning, the corresponding TEM images were obtained. With the pre-treatments analyzed, it appeared impossible to find an acceptable balance between ISH signals and preservation of ultrastructural morphology: when good signal-to-noise ratios are obtained, the ultrastructural morphology is already deteriorated. We discuss the parameters that influence the fragile balance between high RNA detection efficiency and good preservation of ultrastructure and the benefit of RCM monitoring in the development and procedures for pre-embedding electron microscopic ISH.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Investigation of Switching Mechanism in HfO2-Based Oxide Resistive Memories by In-Situ Transmission Electron Microscopy and Electron Energy Loss Spectroscopy

2017 ◽  
Author(s):  
T. Dewolf ◽  
D. Cooper ◽  
N. Bernier ◽  
V. Delaye ◽  
A. Grenier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Hafnium Dioxide ◽  
Switching Mechanism ◽  
Transmission Electron ◽  
Electron Energy Loss

Abstract Forming and breaking a nanometer-sized conductive area are commonly accepted as the physical phenomenon involved in the switching mechanism of oxide resistive random access memories (OxRRAM). This study investigates a state-of-the-art OxRRAM device by in-situ transmission electron microscopy (TEM). Combining high spatial resolution obtained with a very small probe scanned over the area of interest of the sample and chemical analyses with electron energy loss spectroscopy, the local chemical state of the device can be compared before and after applying an electrical bias. This in-situ approach allows simultaneous TEM observation and memory cell operation. After the in-situ forming, a filamentary migration of titanium within the dielectric hafnium dioxide layer has been evidenced. This migration may be at the origin of the conductive path responsible for the low and high resistive states of the memory.

scholarly journals Fabrication of a liquid cell for in situ transmission electron microscopy

Microscopy ◽  
2020 ◽  
Author(s):  
Xiaoguang Li ◽  
Kazutaka Mitsuishi ◽  
Masaki Takeguchi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cost Effective ◽  
Production Method ◽  
Microscopy Imaging ◽  
Transmission Electron ◽  
In Situ Electron Microscopy ◽  
Liquid Cell ◽  
Si Wafer

Abstract Liquid cell transmission electron microscopy (LCTEM) enables imaging of dynamic processes in liquid with high spatial and temporal resolution. The widely used liquid cell (LC) consists of two stacking microchips with a thin wet sample sandwiched between them. The vertically overlapped electron-transparent membrane windows on the microchips provide passage for the electron beam. However, microchips with imprecise dimensions usually cause poor alignment of the windows and difficulty in acquiring high-quality images. In this study, we developed a new and efficient microchip fabrication process for LCTEM with a large viewing area (180 µm × 40 µm) and evaluated the resultant LC. The new positioning reference marks on the surface of the Si wafer dramatically improve the precision of dicing the wafer, making it possible to accurately align the windows on two stacking microchips. The precise alignment led to a liquid thickness of 125.6 nm close to the edge of the viewing area. The performance of our LC was demonstrated by in situ transmission electron microscopy imaging of the dynamic motions of 2-nm Pt particles. This versatile and cost-effective microchip production method can be used to fabricate other types of microchips for in situ electron microscopy.

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