News

The hitchhiking mite

Published 15 June 2011

This mite, one tenth of a millimetre across, was an unexpected find when scientists at the University of Brighton were testing their new state-of-the-art electron microscopes in the university's new £23m Huxley building in Moulsecoomb, Brighton.

The mite, identified by the Natural History Museum as a 'motile hypopus', was imaged as it was taking a ride on a leg of a millipede to search for richer feeding grounds.

The new cryo electron microscopy system, the most advanced in the south-east, produces images sharper and faster than others by freeze drying samples in-situ, enabling the study of samples that would otherwise be impossible to examine.

Dr Jonathan Salvage, Research Fellow in the School of Pharmacy and Biomolecular Sciences, explained how the Quorum Technologies' PP3000T cryo scanning electron microscopy (SEM) system works: "The millipede was collected from a colleague's garden – it was snap frozen in liquid nitrogen at - 196°C and then sublimed under vacuum, a technique providing for the controlled removal of water, and thus freeze dried.

A motile hypopus on the leg of a millipede

"Many samples possess a moisture content which means they cannot immediately be placed in the high vacuum chamber of the SEM as they would boil and de-gas, destroying the sample.

"By snap-freezing the moisture, it is contained and controlled. The sublimation then provides the careful removal of the frozen water by changing it from solid to gas form without it entering a liquid phase. Thus water is removed and the sample's delicate architecture is preserved."

Close-up of a motile hypopus on the leg of a millipede

Dr Salvage, academic lead for the school's Image and Analysis Unit, said the £500,000 system was the first operational instrument of this kind installed in the world and marked a significant breakthrough in electron microscopy sample preparation technology.

He said the complete electron microscopy package, supplied by Zeiss NTS, includes two Zeiss scanning electron microscopes, the Quorum Cryo-SEM system, and two Oxford Instruments elemental analysis systems which will "ensure students and staff across all University of Brighton faculties have access to the most up-to-date teaching and research equipment".

Over 500 children and 36 teachers from 15 schools will be visiting the university and experiencing SEM next month. Dr Salvage said: "As part of the university's social and economic engagement policy the facilities can be accessed for educational visits through the STEM-Sussex network.

"We also cater for commercial research interests, the food industry, for instance, can benefit when they are testing product improvements. The advantage of the new system is the quicker turn-around time for samples – we can now examine twice as many in a day."