Volume 25 Issue 6 September 2011

Tom Levesque, Technology Business Consulting, Lewisville, Texas 75077, USA
Cleanliness within the electron microscope environment is critical to obtaining quality images and data, especially at today’s demanding high resolution and low accelerating voltages. This article discusses historical and current methods that are useful for maintaining hydrocarbon free regimes.

Helfrid Hochegger, Genome Damage and Stability Centre, University of Sussex, Brighton, UK
Chicken DT40 cells have been widely used for genetic studies, but these non-adherent lymphocytes pose a challenge for live cell imaging. We have recently developed protocols to image centrosome separation in these cells using 4D widefield live-cell imaging. The main challenges for imaging these processes in DT40 cells lie in cell immobilization, high-resolution 3D imaging throughout the entire cell volume, and light sensitivity. To overcome these problems we used a personal DeltaVision microscope equipped with a cascade EMCCD in combination with Huygens deconvolution to follow GFP-g-tubulin labelled centrosomes during mitotic cell division and measure velocities of separation. The combination of genetic manipulation of mitotic kinases and 4D microscopy allowed us to unravel a novel mechanism in the control of centrosome separation.

Simon J. Powis, Chin Y. Soo, Ying Zheng, Elaine C. Campbell and Andrew Riches, School of Medicine, University of St Andrews, Scotland
Many cells, including those of the immune system, secrete small vesicles called exosomes or nanovesicles, with a size range of between 50 and 150 nm. These vesicles can display a wide range of immunological functions, including both immunostimulatory and immunosuppressive activities. The possibility of rapidly monitoring the presence and relative quantity of exosomes in both tissue culture supernatants and body fluids by the technique of nanoparticle tracking analysis (NTA) may represent a significant step forward in the characterisation of exosomes.

Archana Mallik, Department of Metallurgical and Materials Engineering, National Institute of Technology, Rourkela, India
Sono-electrochemistry, the coupling of ultrasound to electrochemistry, has long been recognised in materials synthesis for better efficiency and properties. The application of powerful ultrasound radiation (20 kHz to10 MHz) causes acoustic cavitation: creation and collapse of microscopic bubbles inside the liquid medium, which can affect crystallization. We have prepared nanostructured copper powder by ultrasound- assisted electrodeposition with a potentiostatic set-up at sub-ambient deposition temperature. The  powder was found to be highly crystalline. SEM and TEM indicate that the powders synthesized without ultrasound were dendritic in appearance. Sonicated deposits were either faceted or spherical grains consisting of agglomerated as well as isolated particles of variable nanometric (50-70 nm) sizes. The fine powders may readily be used in the preparation of industrial parts through powder metallurgy without further preparation.