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First, there is scope in the future to develop the investigated system of liquid crystalline reservoirs to target specifi c cell types given that, for example, diseased cells are generally believed to have more negative surface charge than healthy ones. Furthermore, researchers of complex drug formulations would be advised to consider effects of gravity in relation to their experimental tests.


Contrast Variation and Isotopic Substitution


– Enhancing the Signal An additional trick used in neutron studies takes advantage of a unique feature - neutrons are scattered differently by different isotopes of the same element and thus can distinguish between hydrogen and deuterium atoms due to their different scattering power. This allows the scattered signal from specifi c molecules to be enhanced through isotopic contrast variation by modifying the ratio of H2O to D2O in the buffer solution.


A similar technique - isotopic substitution - replaces specifi c hydrogen-containing monomers in a biological oligomer with deuterium copies. The label means that the desired region ‘stands out’ during neutron scattering. The technique was recently used to elucidate the 3D structure of the box C/D Box ribonucleoprotein enzyme, responsible for methylation of RNA during ribosome assembly. Individual protein subunits were tagged in turn, allowing the determination of their position within the C/D box complex.


SANS - Small Angle Neutron Scattering


Another popular neutron technique, small angle neutron scattering, is used to look at bulk samples. Beams of neutrons are defl ected by an angle of only a degree or so, and the combination of scattered angles and wavelength are analysed to characterise structures of one to several hundred nanometres within a solution, dispersion or solid sample.


SANS is particularly useful in biology, where it allows the study of interactions in physiological environments and relevant thermodynamic conditions. In a recent study, this technique has been used to study the water purifi cation properties of seeds from Moringa trees. Neutrons were directed at water containing small particles - a model system for waste water - mixed with protein extracted from the seeds. The amount of protein bound to the particles, as well as the formation of aggregates, was observed by measuring the scattering from the samples. The aggregates, known as fl ocs, can be separated from the water and the neutron data show that the aggregates formed with the proteins were more densely packed than those produced by conventional chemicals and could be separated more readily.


Ultracold Neutrons – Studying the Movement


of Particles on Surfaces Recent research has hinted that ultracold neutrons may be able to detect the movement of nanoparticles on surfaces. Ultracold neutrons are studied in ‘traps’, where properties such as their lifetime are determined. Studies at ILL revealed that neutrons collided with moving nanoparticles on surfaces and the interaction gave the neutrons suffi cient energy to overcome gravity and escape from the chamber.


The results provide a possible mechanism to track the movement of particles on surfaces, such as the movement of virus particles on cell membranes. Although at a very early stage, the possible applications of the technique are diverse and exciting.


About ILL


Institut Laue-Langevin (ILL) is an international research centre based in Grenoble, France. It has led the world in neutron-scattering science and technology for almost 40 years, since experiments began in 1972. ILL operates one of the most intense neutron sources in the world, feeding beams of neutrons to a suite of 40 high-performance instruments that are constantly upgraded. Each year 1,200 researchers from over 40 countries visit ILL to conduct research into condensed matter physics, chemistry, biology, nuclear physics, and materials science. The UK, along with France and Germany is an associate and major funder of ILL.


For more information contact: welcome@ill.eu or visit: www.ill.eu Read, Share and Comment on this Article, visit: www.labmate-online.com/articles


Collaboration on High-Throughput Cell-Line Characterisation Services for Regenerative Medicine Announced


Agilent Technologies Inc have announced a collaboration with Cell Line Genetics, Inc, a leading provider of cell-line characterisation and quality assurance services. CLG will develop high-throughput, genomic characterisation workflows to confirm and monitor the integrity of cell lines for translational and regenerative medicine research. The workflows will be based upon Agilent’s custom, targeted CGH+SNP microarrays and SureFISH technology.


“Cell Line Genetics customers in the regenerative medicine research market include leading research institutions, biotechnology and pharmaceutical companies,” said Victor Fung, Agilent’s Senior Director of Global Marketing for the Genomics Solutions Division. “These diverse customers will benefit from services better tailored to meet their needs. In addition, Cell Line Genetics can better control operating costs because targeted array CGH designs can focus probe density where it matters most, enabling much faster data interpretation than SNP microarrays. Speed of analysis is particularly important in this high-throughput environment.


CLG selected Agilent’s genome-wide CGH+SNP microarrays for their capability, in a predictable high-throughput environment, to detect amplifications, deletions and cell line clonality with high sensitivity. CLG will use FISH assays to confirm aberrations identified down to the single-cell level. This approach provides a robust, best-in-class means of characterising genome integrity and purity.


For cancer cell line characterisation, CLG will offer array CGH (aCGH) services as it is able to simultaneously detect a large number of anomalies more accurately, with higher sensitivity, and with better coverage than traditional cytogenetics. In addition, when using aCGH, CLG can offer a faster turnaround time to customers.


After testing more than 15,000 stem cell lines, CLG found that 20% showed aneuploidy, and 60 to 70% of those were mosaic. Most significantly, the cells harbouring genomic anomalies can have a proliferative advantage and overtake the culture, compromising the validity of study data and resulting in the loss of samples, time and funds.


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