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John Fletcher
Professor
Department of Chemistry & Molecular BiologyAbout John Fletcher
My groups research is focused on the development and application of imaging mass spectrometry for biological analysis. Mass spectrometry provides molecular specific chemical information without the need to incorporate exogenous labels. When used in an imaging modality this chemical precision is combined with precise spatial distribution. Secondary ion mass spectrometry (SIMS) uses a focused ion beam to probe the surface of a sample and the nature of the ion beam fired at the sample can ultimately determine what chemical species are detected in the mass spectrometer. As there is a constant demand for more signal at higher resolution and so ion beam development is an active area of research particularly using new gas cluster ion beam technology. For biological sample analysis ensuring that the data generated is representative of the "live" sample means that methods to prepare and analyse biological specimen in the vacuum environment required for imaging SIMS are critical. Combining the new ion beams with optimal sample preperation provides a route to identifying lipidomic changes on a sub-cellular scale, potentially in 3D, in order elucidate the underlying chemical processes involved in disease progression and treatment.
Current group members
Alfred Fransson
Simon Uzoni
Teaching and Departmental Responsibilities
KEM070 - Basic Analytical Chemistry
KEM082 - Advanced Bioanalytical Chemistry
KEA310 - Introduction to Analytical Chemistry
-
Mapping the Molecular Landscape of Human DLBCL by
GCIB-SIMS
Simon Uzoni, Daniele Zanchin, Vasilis Chatzikyriakos, Noora Neittaanmäki, John S. Fletcher
Analytical Chemistry - 2025 -
ToF-SIMS imaging reveals changes in tumor cell lipids during metastatic progression of
melanoma
Noora Neittaanmäki, Oscar Zaar, Kevin Sjogren Cehajic, Kelly Dimovska Nilsson, Dimitrios Katsarelias, Roger Olofsson Bagge, John Paoli, John S. Fletcher
Pigment Cell & Melanoma Research - 2024 -
PCA, PC-CVA, and Random Forest of GCIB-SIMS Data for the Elucidation of Bacterial Envelope Differences in Antibiotic Resistance
Research
Alfred Fransson, Kelly Dimovska Nilsson, Alex Henderson, Anne Farewell, John S. Fletcher
ANALYTICAL CHEMISTRY - 2024 -
Secondary ion mass
spectrometry
Nicholas P. Lockyer, Satoka Aoyagi, John S. Fletcher, Ian S. Gilmore, Paul A.W. van der Heide, Katie L. Moore, Bonnie J. Tyler, Lu Tao Weng
Nature Reviews Methods Primers - 2024 -
Correlative Cellular Mass Spectrometry Imaging and Amperometry Show Dose Dependent Changes in Lipid Composition and
Exocytosis
Inci Barut, Xiulan He, Erol Sener, Sanna Sämfors, Andrew G Ewing, John S. Fletcher
Angewandte Chemie - International Edition - 2023 -
SIMS and electrochemistry correlate dose dependent alterations on
cells
Inci Barut, Xiulan He, Erol Sener, Sanna Sämfors, Andrew G Ewing, John S. Fletcher
Annual Conference on Mass Spectrometry Imaging and Integrated Topics - 2023 -
Cell and tissue imaging by secondary ion mass
spectrometry
Inci Barut, John S. Fletcher
Biointerphases - 2023 -
(CO2)n+, (H2O)n+, and (H2O)n+ (CO2) gas cluster ion beam secondary ion mass spectrometry: analysis of lipid extracts, cells, and Alzheimer’s model mouse brain
tissue
Kelly Dimovska Nilsson, Anthi Karagianni, Ibrahim Kaya, Marcus Henricsson, John S. Fletcher
Analytical and Bioanalytical Chemistry - 2021 -
Correlated fluorescence microscopy and multi-ion beam secondary ion mass spectrometry imaging reveals phosphatidylethanolamine increases in the membrane of cancer cells over-expressing the molecular chaperone subunit CCT
delta
John S. Fletcher, Sanna Sämfors, Josefine Vallin, Andreas Svanström, Julie Grantham
Analytical and Bioanalytical Chemistry - 2021 -
Interrogation of chemical changes on, and through, the bacterial envelope of Escherichia coli FabF mutant using time-of-flight secondary ion mass
spectrometry
Kelly Dimovska Nilsson, Johan Grandén, Anne Farewell, John S. Fletcher
Surface and Interface Analysis - 2021 -
TOF-SIMS imaging reveals tumor heterogeneity and inflammatory response markers in the microenvironment of basal cell
carcinoma
Kelly Dimovska Nilsson, Noora Neittaanmäki, Oscar Zaar, Tina B. Angerer, John Paoli, John S. Fletcher
Biointerphases - 2020 -
Lipid Diversity in Cells and Tissue Using Imaging
SIMS
Sanna Sämfors, John S. Fletcher
Annual Review of Analytical Chemistry - 2020 -
Brain region-specific amyloid plaque-associated myelin lipid loss, APOE deposition and disruption of the myelin sheath in familial Alzheimer's disease
mice
Ibrahim Kaya, Eva Jennische, Stefan Lange, A. T. Baykal, P. Malmberg, John S. Fletcher
Journal of Neurochemistry - 2020 -
Mass Spectrometry Imaging of Cocaine, Drug Removal and Methylphenidate AlterPhospholipids in Drosophila
Brain
Mai H. Philipsen, Nhu TN Phan, John S. Fletcher, Andrew G Ewing
Biorxiv preprint - 2020 -
Spatial Lipidomics Reveals Region and Long Chain Base Specific Accumulations of Monosialogangliosides in Amyloid Plaques in Familial Alzheimer's Disease Mice (5xFAD)
Brain.
Ibrahim Kaya, Eva Jennische, Johan Dunevall, Stefan Lange, Andrew G Ewing, Per Malmberg, Ahmet Tarik Baykal, John S. Fletcher
ACS chemical neuroscience - 2020 -
Multimodal MALDI Imaging Mass Spectrometry Reveals Spatially Correlated Lipid and Protein Changes in Mouse Heart with Acute Myocardial
Infarction
Ibrahim Kaya, Sanna Sämfors, Malin Levin, Jan Borén, John S. Fletcher
Journal of the American Society for Mass Spectrometry - 2020 -
Interplay between Cocaine, Drug Removal, and Methylphenidate Reversal on Phospholipid Alterations in Drosophila Brain Determined by Imaging Mass
Spectrometry
Mai H. Philipsen, Nhu TN Phan, John S. Fletcher, Andrew G Ewing
ACS Chemical Neuroscience - 2020 -
Chemical Changes On, and Through, The Bacterial Envelope in Escherichia coli Mutants Exhibiting Impaired Plasmid Transfer Identified Using Time-of-Flight Secondary Ion Mass
Spectrometry.
Kelly Dimovska Nilsson, Martin Palm, James Hood, Jake Sheriff, Anne Farewell, John S. Fletcher
Analytical chemistry - 2019 -
Localised lipid accumulation detected in infarcted mouse heart tissue using
ToF-SIMS
S. Samfors, Marcus Ståhlman, Martina Klevstig, Jan Borén, John S. Fletcher
International Journal of Mass Spectrometry - 2019 -
Chemical imaging of aggressive basal cell carcinoma using time-of-flight secondary ion mass
spectrometry.
Marwa Munem, Oscar Zaar, Kelly Dimovska Nilsson, Noora Neittaanmäki, John Paoli, John S. Fletcher
Biointerphases - 2018 -
Benefits of NaCl addition for time-of-flight secondary ion mass spectrometry analysis including the discrimination of diacylglyceride and triacylglyceride
ions
S. Samfors, Andrew G Ewing, John S. Fletcher
Rapid Communications in Mass Spectrometry - 2018 -
On-Tissue Chemical Derivatization of Catecholamines Using 4-(N-Methyl)pyridinium Boronic Acid for ToF-SIMS and LDI-ToF Mass Spectrometry
Imaging
Ibrahim Kaya, S. M. Brülls, Johan Dunevall, Eva Jennische, Stefan Lange, J. Martensson, Andrew G Ewing, Per Malmberg, John S. Fletcher
Analytical Chemistry - 2018 -
Mass Spectrometry Imaging Shows Cocaine and Methylphenidate Have Opposite Effects on Major Lipids in Drosophila
Brain
Mai H. Philipsen, Nhu TN Phan, John S. Fletcher, Per Malmberg, Andrew G Ewing
Acs Chemical Neuroscience - 2018 -
Mass Spectrometry Imaging and Integration with Other Imaging Modalities for Greater Molecular Understanding of Biological
Tissues
T. P. Siegel, G. Hamm, J. Bunch, J. Cappell, John S. Fletcher, K. Schwamborn
Molecular Imaging and Biology - 2018 -
Investigating the Role of the Stringent Response in Lipid Modifications during the Stationary Phase in E. coli by Direct Analysis with Time-of-Flight-Secondary Ion Mass
Spectrometry
Patrick M. Wehrli, Tina B. Angerer, Anne Farewell, John S. Fletcher, Johan Gottfries
Analytical Chemistry - 2016 -
Lipid Heterogeneity Resulting from Fatty Acid Processing in the Human Breast Cancer Microenvironment Identified by GCIB-ToF-SIMS
Imaging
Tina B. Angerer, Ylva Magnusson, Göran Landberg, John S. Fletcher
Analytical Chemistry - 2016 -
Evaluation of biomolecular distributions in rat brain tissues by means of ToF-SIMS using a continuous beam of Ar
clusters
Shusuke Nakano, Yuta Yokoyama, Satoka Aoyagi, Naoyuki Himi, John S. Fletcher, Nicholas P. Lockyer, Alex Henderson, John C. Vickerman
Biointerphases - 2016 -
Intact lipid imaging of mouse brain samples: MALDI, nanoparticle-laser desorption ionization, and 40 keV argon cluster secondary ion mass
spectrometry
Amir Saeid Mohammadi, Nhu TN Phan, John S. Fletcher, Andrew G Ewing
Analytical and Bioanalytical Chemistry - 2016 -
Multimodal Imaging of Chemically Fixed Cells in Preparation for
NanoSIMS
Jelena Lovric, Per Malmberg, Bengt R Johansson, John S. Fletcher, Andrew G Ewing
Analytical Chemistry - 2016 -
Cholesterol Alters the Dynamics of Release in Protein Independent Cell Models for
Exocytosis
Neda Najafinobar, Lisa J. Mellander, Michael E. Kurczy, Johan Dunevall, Tina B. Angerer, John S. Fletcher, Ann-Sofie Cans
Scientific Reports - 2016 -
Optimizing sample preparation for anatomical determination in the hippocampus of rodent brain by ToF-SIMS
analysis
Tina B. Angerer, Amir Saeid Mohammadi, John S. Fletcher
Biointerphases - 2016 -
Peptide Fragmentation and Surface Structural Analysis by Means of ToF-SIMS Using Large Cluster Ion
Sources
Y. Yokoyama, S. Aoyagi, M. Fujii, J. Matsuo, John S. Fletcher, N. P. Lockyer, J. C. Vickerman, M. K. Passarelli, R. Havelund, M. P. Seah
Analytical Chemistry - 2016 -
Lipid Structural Effects of Oral Administration of Methylphenidate in Drosophila Brain by Secondary Ion Mass Spectrometry
Imaging
Nhu TN Phan, John S. Fletcher, Andrew G Ewing
Analytical Chemistry - 2015 -
Comparing depth profiling of oxide scale on SOFC interconnect-materials using ToF-SIMS with Ga-69(+), Bi-3(+)/Cs+ and C-60(+)/C-60(2+) as primary and sputter
ions
Josefin Hall, U. Bexell, John S. Fletcher, Sead Canovic, Per Malmberg
Materials at High Temperatures - 2015 -
Improved Molecular Imaging in Rodent Brain with Time-of-Flight-Secondary Ion Mass Spectrometry Using Gas Cluster Ion Beams and Reactive Vapor
Exposure
Tina B. Angerer, Masoumeh Dowlatshahi Pour, Per Malmberg, John S. Fletcher
Analytical Chemistry - 2015 -
Significant Enhancement of Negative Secondary Ion Yields by Cluster Ion Bombardment Combined with Cesium
Flooding
P. Philipp, Tina B. Angerer, Sanna Sämfors, P. Blenkinsopp, John S. Fletcher, T. Wirtz
Analytical Chemistry - 2015 -
3D imaging of biological specimen using
MS
John S. Fletcher
Bioanalysis - 2015 -
Measuring Compositions in Organic Depth Profiling: Results from a VAMAS Interlaboratory
Study
A. G. Shard, R. Havelund, S. J. Spencer, I. S. Gilmore, M. R. Alexander, Tina B. Angerer, S. Aoyagi, J. P. Barnes, A. Benayad, A. Bernasik, G. Ceccone, J. D. P. Counsell, C. Deeks, John S. Fletcher, D. J. Graham, C. Heuser, T. G. Lee, C. Marie, M. M. Marzec, G. Mishra, D. Rading, O. Renault, D. J. Scurr, H. K. Shon, V. Spampinato, H. Tian, F. Y. Wang, N. Winograd, K. Wu, A. Wucher, Y. F. Zhou, Z. H. Zhu
Journal of Physical Chemistry B - 2015 -
Latest applications of 3D ToF-SIMS
bio-imaging
John S. Fletcher
Biointerphases - 2015 -
High energy gas cluster ions for organic and biological analysis by time-of-flight secondary ion mass
spectrometry
Tina B. Angerer, Paul Blenkinsopp, John S. Fletcher
International Journal of Mass Spectrometry - 2015 -
Imaging Mass Spectrometry for Single-Cell
Analysis
Nhu TN Phan, John S. Fletcher, Andrew G Ewing
Reference Module in Chemistry, Molecular Sciences and Chemical Engineering - 2014 -
Spatiotemporal lipid profiling during early embryo development of Xenopus laevis using dynamic Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS)
Imaging
Hua Tian, John S. Fletcher, Raphael Thuret, Alex Henderson, Nancy Papalopulu, John Vickerman, Nicholas Lockyer
Journal of Lipid Research - 2014 -
ToF-SIMS imaging of lipids and lipid related compounds in Drosophila
brain
Nhu TN Phan, John S. Fletcher, Peter Sjövall, Andrew G Ewing
Surface and Interface Analysis: 19th International Conference on Secondary Ion Mass Spectrometry (SIMS) - 2014 -
Analysis of liposome model systems by time-of-flight secondary ion mass
spectrometry
Jelena Lovric, Jacqueline Keighron, Tina B. Angerer, Xianchan Li, Per Malmberg, John S. Fletcher, Andrew G Ewing
Surface and Interface Analysis: 19th International Conference on Secondary Ion Mass Spectrometry (SIMS) - 2014 -
Gold and silver nanoparticle-assisted laser desorption ionization mass spectrometry compatible with secondary ion mass spectrometry for lipid
analysis
Amir Saeid Mohammadi, John S. Fletcher, Per Malmberg, Andrew G Ewing
Surface and Interface Analysis: 19th International Conference on Secondary Ion Mass Spectrometry (SIMS) - 2014 -
Maximising the potential for bacterial phenotyping using time‐of‐flight secondary ion mass spectrometry with multivariate analysis and Tandem Mass
Spectrometry
Patrick M. Wehrli, Erika Lindberg, Tina B. Angerer, Agnes E Wold, Johan Gottfries, John S. Fletcher
Surface and Interface Analysis - 2014 -
Prospect of increasing secondary ion yields in ToF-SIMS using water cluster primary ion
beams
S. Sheraz, A. Barber, I. B. Razo, John S. Fletcher, N. P. Lockyer, J. C. Vickerman
Surface and Interface Analysis - 2014 -
3D Imaging of TiO2 nanoparticle accumulation in tetrahymena
pyriformis
Tina B. Angerer, John S. Fletcher
Surface and Interface Analysis - 2014 -
Examination of fragment ions of polystyrene in TOF-SIMS spectra using
MS/MS
T. Kawashima, T. Kurosawa, S. Aoyagi, S. Sheraz, John S. Fletcher, M. Futigami, N. P. Lockyer, J. C. Vickerman
Surface and Interface Analysis - 2014 -
Time-of-Flight Secondary Ion Mass Spectrometry Based Molecular Histology of Human Spinal Cord Tissue and Motor
Neurons
Jörg Hanrieder, Per Malmberg, Olle R Lindberg, John S. Fletcher, Andrew G Ewing
Analytical Chemistry - 2013
More publications
We have limited the number of publications on this page. Visit GUP (The Publication Database for Gothenburg University) to find more publications.