Protochips (United States)

Abstract: The interaction of the electron beam with materials during TEM/STEM imaging often leads to radiation damage. While a variety of low-dose techniques can help mitigate beam damage, true dose management starts with knowing the precise total accumulated dose and dose rate that a sample has seen throughout an experiment. AXON Dose allows users to calibrate their instruments, track electron dose/dose rate across a sample as a function of time and location, and quantify the impact of dose on individual samples.

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Journal Article Introducing and Controlling Water Vapor in Gas-Cell Microscopy Experiments Get access K A Unocic, K A Unocic Materials Science & Technology Div., Oak Ridge National Laboratory, Oak Ridge, TN, USA Search for other works by this author on: Oxford Academic Google Scholar F S Walden, F S Walden Protochips Inc., Morrisville, NC, USA Search for other works by this author on: Oxford Academic Google Scholar N L Marthe, N L Marthe Protochips Inc., Morrisville, NC, USA Search for other works by this author on: Oxford Academic Google Scholar W C Bigelow, W C Bigelow Department of Materials Science & Engineering, University of Michigan, Ann Arbor, MI, USA Search for other works by this author on: Oxford Academic Google Scholar L F Allard L F Allard Materials Science & Technology Div., Oak Ridge National Laboratory, Oak Ridge, TN, USA Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 25, Issue S1, 1 February 2019, Pages 35–36, https://doi.org/10.1017/S1431927618015908 Published: 01 February 2019

Journal Article In situ TEM imaging of Nanoparticles interacting with Glioblastoma Stem Cells Get access Elliot S Pohlmann, Elliot S Pohlmann Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA 24016, USA Search for other works by this author on: Oxford Academic Google Scholar Kaya Patel, Kaya Patel Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA 24016, USA Search for other works by this author on: Oxford Academic Google Scholar Sujuan Guo, Sujuan Guo Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA 24016, USA Search for other works by this author on: Oxford Academic Google Scholar Madeline J Dukes, Madeline J Dukes Applications Science, Protochips, Inc., Raleigh, NC, 97606, USA Search for other works by this author on: Oxford Academic Google Scholar Zhi Sheng, Zhi Sheng Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA 24016, USA Search for other works by this author on: Oxford Academic Google Scholar Deborah F Kelly Deborah F Kelly Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA 24016, USA Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 21, Issue S3, 1 August 2015, Pages 1297–1298, https://doi.org/10.1017/S1431927615007278 Published: 23 September 2015

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Journal Article Applications and Design of Reinforced Silicon Nitride Windows for In Situ Liquid Transmission Electron Microscopy Get access Madeline J Dukes, Madeline J Dukes Protochips, Inc. Raleigh, NC 27606, USA Search for other works by this author on: Oxford Academic Google Scholar Albert D Dukes, Albert D Dukes Lander University, Department of Physical Sciences, Greenwood, SC 29649, USA Search for other works by this author on: Oxford Academic Google Scholar Kate L Klein, Kate L Klein Department of Mechanical Engineering, University of the District of Columbia, Washington, DC 20008, USA Search for other works by this author on: Oxford Academic Google Scholar Rebecca Thomas, Rebecca Thomas Protochips, Inc. Raleigh, NC 27606, USA Search for other works by this author on: Oxford Academic Google Scholar Deborah F Kelly, Deborah F Kelly Virginia Tech Carilion Research Institute, Virginia Tech, Roanoke, VA 24016, USA Search for other works by this author on: Oxford Academic Google Scholar John Damiano John Damiano Protochips, Inc. Raleigh, NC 27606, USA Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 20, Issue S3, 1 August 2014, Pages 1090–1091, https://doi.org/10.1017/S143192761400717X Published: 27 August 2014

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Here we present new applications for silicon nitride (SiN) membranes to evaluate biological processes. We determined that 50-nanometer thin films of SiN produced from silicon wafers were sufficiently durable to bind active rotavirus assemblies. A direct comparison of SiN microchips with conventional carbon support films indicated that SiN performs equivalent to the traditional substrate to prepare samples for Electron Microscopy (EM) imaging. Likewise, SiN films coated with Ni-NTA affinity layers concentrated rotavirus particles similarly to affinity-coated carbon films. However, affinity-coated SiN membranes outperformed glow-discharged conventional carbon films 5-fold as indicated by the number of viral particles quantified in EM images. In addition, we were able to recapitulate viral uncoating and transcription mechanisms directed onto the microchip surfaces. EM images of these processes revealed the production of RNA transcripts emerging from active rotavirus complexes. These results were confirmed by the functional incorporation of radiolabeled nucleotides into the nascent RNA transcripts. Collectively, we demonstrate new uses for SiN membranes to perform molecular surveillance on life processes in real-time.

The use of in situtransmission electron microscopy (TEM) to study biological processes is a new frontier in high-resolution imaging. Here we report the development of affinity capture devices that are used to isolate biological entities for in situ studies. Affinity capture devices are silicon nitride microchips coated with functionalized lipid monolayers. We tested the isolation capacity of the devices by using protein synthesis machinery as a test specimen for single particle and in situTEM analysis. Overall, we demonstrate the feasibility of purifying biological assemblies in a liquid environment within a TEM column. This novel application may serve to bridge the gap between cellular and molecular imaging techniques.

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.