University College London's School of Pharmacy is one of the top rated pharmacy schools in the UK having built a long tradition of academic and research excellence. Within its Pharmacology Group is the Electron Microscopy Unit, which was started and managed from 1977 by David McCarthy and which uses a number of advanced electron microscopes from FEI. These provide essential support services to the School’s research programmes.
Led by McCarthy, who has expertise in TEM/SEM/LM of pharmaceutical preparations and drug delivery systems, the unit is currently focused on providing a contract service mainly imaging drug delivery carriers, which are usually low melting point polymers that may be thermally or vacuum sensitive.
Delivering sharp, clear images is the focus of the unit and the adoption of an Evactron downstream plasma cleaning unit from XEI Scientific/Acutance has proved an excellent investment. Degradation of biological samples at 37°C results in hydrocarbon contamination around the sharp end of the microscope column.
This results in the microscope behaving erratically because of charging. For example, if the operator wishes to change the beam energy or magnification, the system starts to behave unpredictably. This may result in the image shooting off to one side or distorting, which means the column needs to be realigned. This causes poor performance at low beam energies. The addition of the Evactron system to clean contamination off the sharp end of the column has resulted in a much more predictable and usable system at low beam energies.
As McCarthy observes: “As samples breakdown causing contamination, I see astigmatism issues. When this happens, I know it is time for a clean!”
The Evactron is the most cost-efficient cleaning system offered by XEI Scientific. The Evactron De-Contaminator uses a remote RF plasma source to produce gas-phase radicals that flow downstream through the chamber, eliminating contamination by chemical etch.
