Speaker
Dr
Geoffrey Grime
(University of Surrey Ion Beam Centre, Guildford, U.K.)
Description
As we have described previously [1,2], microbeam PIXE combined with simultaneous RBS analysis is the only accurate method easily available for identifying and quantifying the small number of metal atoms commonly present in large biological molecules such as proteins.
This method has been in routine use at the Surrey Ion Beam Centre for several years, but is restricted in its range of applications because preparing, loading, positioning and analysing single samples by hand is time consuming and it is difficult to analyse more than ten samples in a typical working day. Many bio-science experiments are now designed on a 'high throughput' model where many samples are prepared in different ways or exposed to different reagents and the results analysed using automated methods such as optical fluorescence. Although metal atom determination using microPIXE would be desirable for many of these sample sets, analysing such large sample numbers by hand is totally impractical.
We have now developed a high-throughput method for analysing large sample sets which has significantly extended the application of the technique. The samples are deposited as arrays of spots using a non-contact ink-jet printer. These are then analysed sequentially using pattern recognition techniques to localise the spots under the beam, real-time spectrum evaluation to determine the end-point of the analysis and batch spectrum processing to determine the concentrations. This paper describes the method and presents some illustrative results.
[1] 'Leaving no element of doubt: analysis of proteins using microPIXE.' Elspeth Garman. Structure (1999) 7, R291-299.
[2] 'Elemental analysis of proteins by microPIXE.' Elspeth Garman and Geoff Grime, Progress in Biophysics and Molecular Biology (2005) 89/2, 173-205.
Primary author
Dr
Geoffrey Grime
(University of Surrey Ion Beam Centre, Guildford, U.K.)
Co-authors
Prof.
Elspeth Garman
(Department of Biochemistry, University of Oxford, Oxford, U.K.)
Dr
Oliver Zeldin
(Departments of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, United States)
