title: 3D imaging of transition metals in the zebrafish embryo by X-ray fluorescence microtomography.
abstract: Synchrotron X-ray fluorescence (SXRF) microtomography has emerged as a powerful technique for the 3D visualization of the elemental distribution in biological samples. The mechanical stability, both of the instrument and the specimen, is paramount when acquiring tomographic projection series. By combining the progressive lowering of temperature method (PLT) with femtosecond laser sectioning, we were able to embed, excise, and preserve a zebrafish embryo at 24 hours post fertilization in an X-ray compatible, transparent resin for tomographic elemental imaging. Based on a data set comprised of 60 projections, acquired with a step size of 2 μm during 100 hours of beam time, we reconstructed the 3D distribution of zinc, iron, and copper using the iterative maximum likelihood expectation maximization (MLEM) reconstruction algorithm. The volumetric elemental maps, which entail over 124 million individual voxels for each transition metal, revealed distinct elemental distributions that could be correlated with characteristic anatomical features at this stage of embryonic development.
authors.affiliation: School of Chemistry and Biochemistry and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332, USA. fahrni@chemistry.gatech.edu.
authors.forename: Daisy
authors.initials: D
authors.lastname: Bourassa
authors.forename: Sophie-Charlotte
authors.initials: SC
authors.lastname: Gleber
authors.forename: Stefan
authors.initials: S
authors.lastname: Vogt
authors.forename: Hong
authors.initials: H
authors.lastname: Yi
authors.forename: Fabian
authors.initials: F
authors.lastname: Will
authors.forename: Heiko
authors.initials: H
authors.lastname: Richter
authors.forename: Chong Hyun
authors.initials: CH
authors.lastname: Shin
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Fahrni
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D005453:Fluorescence; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007834:Lasers; D013997:Time Factors; D028561:Transition Elements / Q000378:metabolism*; D055114:X-Ray Microtomography / Q000379:methods*; D015027:Zebrafish / Q000196:embryology*
chemical_list: D028561:Transition Elements