Novel sample preparation approaches for LDI imaging MS to answer key biological questions
Applied Mass Spectrometry [food/nutrition/environment and agriculture] @ McGill - Macdonald Campus
Guest speaker: Prof Pierre Chaurand, Department of Chemistry, Université de Montréal
Imaging mass spectrometry (IMS) has become the leading technique for the analysis of biomolecules directly from thin tissue sections while retaining the biomolecules’ anatomical distributions. In recent years, MALDI IMS as greatly improved in spatial resolution due to the advancement in both sample preparations and instruments to the point of reaching cellular level capabilities. In this workshop, after giving an overview of IMS technology and of its potential, new developments in IMS from our laboratory to increase specificity and sensitivity will be presented. More specifically, matrix-free metal assisted LDI IMS methods have been developed for the specific analysis of neutral lipid compounds. For these, nanometer thin metal layers are directly sputter deposited on tissue sections. From the investigation of various tissue specimens, using silver-assisted LDI IMS we have thus far mapped and identified several compounds including, cholesterol, arachidonic acid and docosahexaenoic acid. While both fatty acids and cholesterol show great affinity for silver, other molecules such as triglycerides have strong affinities for sodium cations. For this purpose, the coupling of sodium salts and sputtered layers of gold has been developed to enhance both desorption and ionization of triglycerides yielding a 30-fold increase in signal compared to standard MALDI MS approaches. Although gold-assisted LDI IMS targets triglycerides, we have also detected and imaged several other compounds including cholesterol esters, which are hard to detect by MALDI MS. The clinical potentials of these novel IMS strategies for the detection and characterization of molecular changes in disease has been exemplified through studies of Alzheimer’s and non-alcoholic fatty liver diseases.
ABOUT THE SPEAKER
Pierre Chaurand received his Ph.D. in physical chemistry from the Université Paris Sud, (Orsay, France) in 1994. After a postdoctoral period at the Heinrich-Heine Universität, (Düsseldorf, Germany), he integrated in 1998 the laboratory of Prof. Richard Caprioli as Research Faculty at Vanderbilt University School of Medicine (Nashville TN, USA). Since 2009, he is Professor in the Department of Chemistry at the Université de Montréal (Montreal, Canada). His primary background is in biochemistry with significant analytical and organic chemistry components. His current expertise’s are in fundamental and analytical mass spectrometry. With over 20 years of experience in the field, he is one of the pioneers of the imaging mass spectrometry (IMS) technology. His current research interests are focused on the development of new strategies and methods to improve the specificity and sensitivity of tissue based IMS with applications in fundamental and clinical biology.
Everyone is welcome to attend.