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Rapid and Accurate Analysis of an X-Ray Fluorescence Microscopy Data Set through Gaussian Mixture-Based Soft Clustering Methods

Published online by Cambridge University Press:  07 August 2013

Jesse Ward
Affiliation:
X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
Rebecca Marvin
Affiliation:
Department of Chemistry and Chemistry of Life Processes, Northwestern University, Evanston, IL 60208, USA
Thomas O'Halloran
Affiliation:
Department of Chemistry and Chemistry of Life Processes, Northwestern University, Evanston, IL 60208, USA Interdepartmental Biological Sciences, Northwestern University, Evanston, IL 60208, USA
Chris Jacobsen
Affiliation:
X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA
Stefan Vogt*
Affiliation:
X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
*
*Corresponding author. E-mail: svogt@aps.anl.gov
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Abstract

X-ray fluorescence (XRF) microscopy is an important tool for studying trace metals in biology, enabling simultaneous detection of multiple elements of interest and allowing quantification of metals in organelles without the need for subcellular fractionation. Currently, analysis of XRF images is often done using manually defined regions of interest (ROIs). However, since advances in synchrotron instrumentation have enabled the collection of very large data sets encompassing hundreds of cells, manual approaches are becoming increasingly impractical. We describe here the use of soft clustering to identify cell ROIs based on elemental contents, using data collected over a sample of the malaria parasite Plasmodium falciparum as a test case. Soft clustering was able to successfully classify regions in infected erythrocytes as “parasite,” “food vacuole,” “host,” or “background.” In contrast, hard clustering using the k-means algorithm was found to have difficulty in distinguishing cells from background. While initial tests showed convergence on two or three distinct solutions in 60% of the cells studied, subsequent modifications to the clustering routine improved results to yield 100% consistency in image segmentation. Data extracted using soft cluster ROIs were found to be as accurate as data extracted using manually defined ROIs, and analysis time was considerably improved.

Type
Techniques and Software Development
Copyright
Copyright © Microscopy Society of America 2013 

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References

Benavides, M.P., Gallego, S.M. & Tomaro, M.L. (2005). Cadmium toxicity in plants. Braz J Plant Physiol 17, 2134.CrossRefGoogle Scholar
Bezdek, J.C. (1981). Pattern Recognition with Fuzzy Objective Function Algorithms. Norwell, MA: Kluwer Academic Publishers.CrossRefGoogle Scholar
Chitambar, C.R. (2005). Cellular iron metabolism: Mitochondria in the spotlight. Blood 105(5), 18441845.CrossRefGoogle ScholarPubMed
de Jonge, M.D., Holzner, C., Baines, S.B., Twining, B.S., Ignatyev, K., Diaz, J., Howard, D.L., Legnini, D., Miceli, A., McNulty, I., Jacobsen, C.J. & Vogt, S. (2010). Quantitative 3D elemental microtomography of Cyclotella meneghiniana at 400-nm resolution. Proc Nat Acad Sci 107(36), 1567615680.CrossRefGoogle ScholarPubMed
Dismukes, G.C. (1986). The metal centers of the photosynthetic oxygen-evolving complex. Photochem Photobiol 43(1), 99115.CrossRefGoogle Scholar
Dolman, N.J. & Tepikin, A.V. (2006). Calcium gradients and the Golgi. Cell Calcium 40(5-6), 505512.CrossRefGoogle ScholarPubMed
Everitt, B. (1980). Cluster Analysis. New York: Wiley.Google Scholar
Francis, S.E., Sullivan, D.J. & Goldberg, A.D.E. (1997). Hemoglobin metabolism in the malaria parasite Plasmodium falciparum . Annu Rev Microbiol 51(1), 97123.CrossRefGoogle ScholarPubMed
Ginsburg, H., Gorodetsky, R. & Krugliak, M. (1986). The status of zinc in malaria (Plasmodium falciparum) infected human red blood cells: Stage dependent accumulation, compartmentation and effect of dipicolinate. Biochim Biophys Acta 886(3), 337344.CrossRefGoogle ScholarPubMed
Kaim, W. & Schwederski, B. (1994). Bioinorganic Chemistry: Inorganic Elements in the Chemistry of Life: An Introduction and Guide. San Francisco, CA: John Wiley & Sons.Google Scholar
Keenan, M.R. & Kotula, P.G. (2004). Accounting for Poisson noise in the multivariate analysis of ToF-SIMS spectrum images. Surf Interface Anal 36(3), 203212.CrossRefGoogle Scholar
Keller, J.N., Kindy, M.S., Holtsberg, F.W., St. Clair, D.K., Yen, H.-C., Germeyer, A., Steiner, S.M., Bruce-Keller, A.J., Hutchins, J.B. & Mattson, M.P. (1998). Mitochondrial manganese superoxide dismutase prevents neural apoptosis and reduces ischemic brain injury: Suppression of peroxynitrite production, lipid peroxidation, and mitochondrial dysfunction. J Neurosci 18(2), 687697.CrossRefGoogle ScholarPubMed
Lerotic, M., Jacobsen, C., Gillow, J.B., Francis, A.J., Wirick, S., Vogt, S. & Maser, J. (2005). Cluster analysis in soft X-ray spectromicroscopy: Finding the patterns in complex specimens. J Electron Spectros Relat Phenomena 144147, 11371143.CrossRefGoogle Scholar
Lerotic, M., Jacobsen, C., Schäfer, T. & Vogt, S. (2004). Cluster analysis of soft X-ray spectromicroscopy data. Ultramicroscopy 100(1-2), 3557.CrossRefGoogle ScholarPubMed
Marvin, R.G., Wolford, J.L., Kidd, M.J., Murphy, S., Ward, J., Que, E.L., Mayer, M.L., Penner-Hahn, J.E., Haldar, K. & O'Halloran, T.V. (2012). Fluxes in “free” and total zinc are essential for progression of intraerythrocytic stages of Plasmodium falciparum . Chem Biol 19(6), 731741.CrossRefGoogle ScholarPubMed
Moon, T.K. (1996). The expectation-maximization algorithm. IEEE Signal Process Mag 13(6), 4760.CrossRefGoogle Scholar
Muller, S. (2004). Redox and antioxidant systems of the malaria parasite Plasmodium falciparum . Mol Microbiol 53(5), 12911305.CrossRefGoogle ScholarPubMed
Paunesku, T., Vogt, S., Maser, J., Lai, B. & Woloschak, G. (2006). X-ray fluorescence microprobe imaging in biology and medicine. J Cell Biochem 99(6), 14891502.CrossRefGoogle ScholarPubMed
Stork, C.L. & Keenan, M.R. (2010). Advantages of clustering in the phase classification of hyperspectral materials images. Microsc Microanal 16(6), 810820.CrossRefGoogle ScholarPubMed
Trager, W. & Jensen, J. (1976). Human malaria parasites in continuous culture. Science 193(4254), 673675.CrossRefGoogle ScholarPubMed
Vallee, B.L., Coleman, J.E. & Auld, D.S. (1991). Zinc fingers, zinc clusters, and zinc twists in DNA-binding protein domains. Proc Natl Acad Sci USA 88(3), 9991003.CrossRefGoogle ScholarPubMed
Vogt, S. (2003). MAPS: A set of software tools for analysis and visualization of 3D X-ray fluorescence data sets. J Physiq (Proc) 104(2), 635638.Google Scholar