News from Quorum: The Agricultural Research Service of the USDA uses a Quorum Cryo-SEM preparation system for the study of mites, ticks and other soft bodied organisms

Laughton, United Kingdom, 22nd November 2016: Quorum Technologies, market and technology leaders in electron microscopy coating and cryogenic preparation products, report on the work of the Agricultural Research Service of the US Department of Agriculture where their PP2000 Cryo-SEM preparation system is in use to prepare soft bodied organisms including mites & ticks for study using cryo-SEM Dr Gary Bauchan is the Director of the Electron and Confocal Microscopy Unit at the Agricultural Research Service (ARS), the principal in-house research agency of the United States Department of Agriculture. The Unit is a core facility with the responsibility of providing collaborative assistance to scientists from ARS, Northeast Area and Beltsville Agricultural Research Center (BARC) who have microscopy applications that require high resolution imaging. Dr Bauchan’s team have produced images using electron microscopes of bacteria, fungi, mites, insects, nematodes and parasites along with plant and animal tissues both healthy and diseased. One of his major collaborations is with Dr Ron Ochoa, the world’s expert on plant feeding mites. Biological specimens require special treatment due to the high water content of the samples. Many of the specimens are in liquid cultures or are very soft-bodied and by using classical preparative techniques will either destroy the specimen or distort the specimen producing artefacts. A cryo-prep system is an ultra-fast method to ready the specimens for observation in a SEM especially a high resolution field emission SEM. Thus, specimens are frozen in time to allow for observation of feeding behaviour, mating behaviour, host/parasite interactions, etc. It preserves the natural orientation of ultrafine structures such as setae, antenna, legs, skin texture, sensory organs, waxy coatings and eggs. Asked about his experience using a Quorum PP2000 Cryo-SEM preparation system on the Hitachi S-4700 field emission scanning electron microscope, Dr Bauchan said “The Quorum system is easy to use, the set-up for imaging is logical, durable, reliable, and maintains ultra-low temperatures for a long period of time. Holders containing pre-frozen samples are transferred into the cryo-prep chamber where they are etched to remove any surface contamination (condensed water vapour) by raising the temperature of the stage from -130 ºC  to -90 °C for 10-15 minutes. Following etching, the temperature inside the chamber was lowered below -130 °C, and the specimens were coated with a 10 nm layer of platinum using a magnetron sputter head equipped with a platinum target. The specimens were transferred to a pre-cooled (-130 °C) cryo-stage in the SEM for observation.” The system has been used in multiple projects by the Unit, many of which have been published with the generation of stunning, colourful images. The use of low temperature SEM has been shown time and again to be the best method for the examination of microscopic biological specimens and their ultrastructure. The work in conjunction with Dr Ochoa has been particularly productive with five papers published this year to date. These have focused on the field of acarology, a branch of zoology dealing with the study of mites and ticks. The PP2000 is one of Quorum’s highly automated, easy-to-use, column-mounted, gas-cooled cryo-SEM preparation systems suitable for most makes and models of SEM, FE-SEM and FIB/SEM. To obtain full details of the latest cryo-SEM preparation systems and other products available from Quorum Technologies, please visit www.quorumtech.com. Note to editors from USDA-ARS: “Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA.” About Quorum Technologies Quorum Technologies are market and technology leaders in electron microscopy (EM) coating and cryogenic preparation. The company was founded in 2001 after the acquisition of the long-established Polaron brand and its range of EM products from Thermo Instruments. In 2005, Quorum acquired the Emitech company allowing the extension of their product range and further growth of the business. Since the start, Quorum has responding to industry requests and requirements for new instruments and techniques. This first culminated in the introduction of the market-leading Q Series of vacuum coaters and PP3010T cryo preparation system for SEM and FIB/SEM – true ground-up redesigns that have truly set the standard within the specimen preparation field. Further impetus and investment came with the acquisition of Quorum by Judges Scientific plc and a move to purpose-built factory and offices close to the South Downs National Park at Laughton, East Sussex in the South East of England. In 2014 Quorum were proud winners of the Queen’s Award for Enterprise for International Trade.

< | >