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National Physical Laboratory

6 ARTICLES PUBLISHED IN JoVE

Biology

Test Samples for Optimizing STORM Super-Resolution Microscopy

Daniel J. Metcalf¹, Rebecca Edwards¹, Neelam Kumarswami¹, Alex E. Knight¹

¹Analytical Science Division, National Physical Laboratory

We describe the preparation of three test samples and how they can be used to optimize and assess the performance of STORM microscopes. Using these examples we show how to acquire raw data and then process it to acquire super-resolution images in cells of approximately 30-50 nm resolution.

Tip-Enhanced Raman Spectroscopy (TERS) Imaging of Grapheme

Andrew Pollard¹, Naresh Kumar¹, Weitao Su², Debdulal Roy¹

¹National Physical Laboratory, ²Institute of Material Physics, Hangzhou Dianzi University

A comprehensive methodology is described for overcoming experimental obstacles encountered when using tip-enhanced Raman spectroscopy (TERS) to map the properties of graphene surfaces. Critical steps, such as the optical alignment of the system, the preparation of TERS probes and the operational TERS procedure required to obtain consistent results, are outlined.

Biology

Green Fluorescent Protein-based Expression Screening of Membrane Proteins in Escherichia coli

Louise E. Bird¹, Heather Rada¹, Anil Verma¹, Raphael Gasper^2,3, James Birch⁴, Matthew Jennions⁴, Jan Lӧwe³, Isabel Moraes⁴, Raymond J. Owens¹

¹Oxford Protein Production Facility, Research Complex at Harwell, ²Protein Crystallography Group, Ruhr University, ³MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, ⁴Membrane Protein Laboratory, Diamond Light Source

A streamlined approach to screening for the expression of recombinant membrane proteins in Escherichia coli based on fusion to green fluorescent protein is presented.

Environment

Dispersion of Nanomaterials in Aqueous Media: Towards Protocol Optimization

Inder Kaur¹, Laura-Jayne Ellis¹, Isabella Romer¹, Ratna Tantra², Marie Carriere^3,4, Soline Allard⁵, Martine Mayne-L'Hermite⁵, Caterina Minelli⁶, Wolfgang Unger⁷, Annegret Potthoff⁸, Steffi Rades⁷, Eugenia Valsami-Jones¹

¹School of Geography, Earth and Environmental Sciences, University of Birmingham, ²Analytical Science, National Physical Laboratory, ³INAC-LCIB, Université Grenoble Alpes, ⁴CEA, INAC-SyMMES, ⁵NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay, ⁶Chemical, Medical and Environmental Science, National Physical Laboratory, ⁷BAM Division 6.1 'Surface Analysis and Interfacial Chemistry', BAM Federal Institute for Materials Research and Testing, ⁸Fraunhofer Institute for Ceramic Technologies and Systems

Here, we present a step-wise protocol for the dispersion of nanomaterials in aqueous media with real-time characterization to identify the optimal sonication conditions, intensity, and duration for improved stability and uniformity of nanoparticle dispersions without impacting the sample integrity.

Biochemistry

High-Throughput Protein Crystallization via Microdialysis

Tristan O. C. Kwan¹, Amy E. Danson¹, Pascelle Draper², Paul Reardon², Isabel Moraes¹

¹National Physical Laboratory, ²SWISSCI LTD

The presented protocol describes a straightforward approach for screening protein crystallization conditions and crystal growth using a 96-well high-throughput dialysis plate. The use of dialyzer tubes for the large-scale growth of microcrystals is also demonstrated for serial crystallography and MicroED applications.

Medicine

A Stable Phantom Material for Optical and Acoustic Imaging

Lina Hacker^1,2, Aoife M. Ivory³, James Joseph^4,5, Janek Gröhl^1,2, Bajram Zeqiri³, Srinath Rajagopal³, Sarah E. Bohndiek^1,2

¹Department of Physics, University of Cambridge, ²Cancer Research UK Cambridge Institute, University of Cambridge, ³Ultrasound and Underwater Acoustics Group, Department of Medical, Marine and Nuclear Physics, National Physical Laboratory, ⁴School of Science and Engineering, University of Dundee, ⁵Centre for Medical Engineering and Technology, University of Dundee

This protocol describes the fabrication of a stable, biologically relevant phantom material for optical and acoustic biomedical imaging applications, featuring independently tunable acoustic and optical properties.