X-ray microanalysis

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=82 BGCOLOR="#006699" TEXT="#080000"> <div> <FONT SIZE="5" COLOR="#FFFFFF" FACE="Arial" ><B>Martin Hodson</B></FONT><B>     |     </B><A HREF="index.html" TARGET="_top" TITLE="Martin Hodson"><U><B>home</B></U></A></div> <div> <B>X-RAY MICROANALYSIS</B></div> <div> </div> </td> </tr><tr> <td valign="top" width=210 BGCOLOR="#FFCC66" TEXT="#080000"> <div> <IMG SRC="076c6b00.jpg" border=0 width="198" height="176" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> </td> <td valign="top" height=398 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <I>X-ray microanalysis</I></div> <div> X-ray microanalysis is a technique that electron microscopists use to locate elements- for biologists it has proved very useful, giving us insights into elemental localization at the cellular or even subcellular level.</div> <div> My first experience of using x-ray microanalysis to investigate mineral localization in plants was in the late 1970's during my Ph.D. work in Swansea. There I used silver salts to precipitate chloride ions in the leaves and roots of the grass <I>Agrostis stolonifera</I>. We used microanalysis to prove that the precipitates we were seeing really were AgCl. Some of the results were published in:</div> <div> SMITH, M.M., HODSON, M.J., ÖPIK, H. & WAINWRIGHT, S.J. (1982) Salt-induced ultrastructural damage to mitochondria in root tips of a salt-sensitive ecotype of <I>Agrostis stolonifera</I>. <I>Journal of Experimental Botany</I> <B>33</B>, 886-895.</div> <div> I then moved to Bangor, and started work on silica deposition in plants. In general terms this is easier to do, as once deposited silica tends to stay where it is! However, I soon started getting interested in how we might locate the soluble silica on its way to deposition sites. This work really took off during my year at York University, Toronto (1987). We used two methods, cryo-SEM and freeze substitution prior to TEM. A good example, including both methods is:</div> <div> HODSON, M.J. & SANGSTER, A.G. (1989) Subcellular localization of mineral deposits in the roots of wheat (<I>Triticum aestivum</I> L.). <I>Protoplasma </I><B>151</B>, 19-32.</div> <div> In Birmingham, UK, I used freeze substitution again, but this time to look at aluminium localization in the spruce root:</div> <div> HODSON, M.J. & WILKINS, D.A. (1991) Localization of aluminium in the roots of Norway spruce [<I>Picea abies</I> (L.) Karst.] inoculated with <I>Paxillus involutus</I> Fr. <I>New Phytologist</I> <B>118</B>, 273-278.</div> <div> My interest in microanalysis continued through the 90's, and this led to my being invited to review the topic:</div> <div> HODSON, M.J. (1995) Ion localization and x-ray microanalysis. In <I>Methods in Plant Cell Biology, Part A</I>. eds. D.W. Galbraith, H.J. Bohnert & D.P. Bourque. Academic Press. <I>Methods in Cell Biology</I> <B>49</B>, 21-31.</div> <div> <A HREF="http://latin.arizona.edu/~dgalbrai/acad49.html" TARGET="_top" TITLE="http://latin.arizona.edu/~dgalbrai/acad4"><U>Link to Methods in Cell Biology 49</U></A></div> <div> I continued my collaboration with Allan Sangster in Toronto, and we were able to make use of the state-of-the-art cryo-SEM facilities at Carleton University in Ottawa to investigate mineral localization in the spruce needle:</div> <div> HODSON, M.J. & SANGSTER, A.G. (1998) Mineral deposition in the needles of white spruce [<I>Picea glauca</I> (Moench.) Voss]. <I>Annals of Botany </I><B>82</B>, 375-385.</div> <bR> <div> In 1999 I was invited to write another review of x-ray microanalysis in plant science and this was published in June 2000:</div> <div> HODSON, M.J. (2000) Microanalysis. In <I>Methods in Plant Electron Microscopy and Cytochemistry</I>.  (ed. W.V. Dashek) Humana Press Inc., Totowa, NJ. 263-278.</div> <div> Details of this book can be found at the Humana Press site:</div> <div> <A HREF="http://www.humanapress.com/" TARGET="_top" TITLE="http://www.humanapress.com/"><U>Humana Press Inc</U></A></div> <div> If you then type "Plant" in their search engine you should find-</div> <div> <B>"Plant Electron Microscopy and Cytochemistry."</B> Edited by: William V. Dashek. (Mary Baldwin College, Richmond, VA) Price: $79.50</div> <div> From that page you can go to another giving you the complete book contents.</div> <div> The description of the book from Humana Press is:</div> <div> "This book highlights the latest techniques for using electron microscopy and cytochemical methods in plant biology. It covers the latest advances in conventional transmission and scanning electron microscopy as well as modern techniques including high resolution radioautography, immunoelectron microscopy, x-ray microanalysis and electron systems imaging. Also covered are atomic force and scanning tunneling microscopies, and recent advances in fluorescence, confocal and dark-field microscopy thus making this an invaluable source of step-by-step techniques for all plant biologists."</div> </td> </tr></table></body>