title: Fast-scanning high-flux microprobe for biological X-ray fluorescence microscopy and microXAS.
abstract: There is a growing interest in the biomedical community in obtaining information concerning the distribution and local chemical environment of metals in tissues and cells. Recently, biological X-ray fluorescence microscopy (XFM) has emerged as the tool of choice to address these questions. A fast-scanning high-flux X-ray microprobe, built around a recently commissioned pair of 200 mm-long Rh-coated silicon Kirkpatrick-Baez mirrors, has been constructed at BioCAT beamline 18ID at the Advanced Photon Source. The new optical system delivers a flux of 1.3 x 10(12) photons s(-1) into a minimum focal spot size of approximately 3-5 microm FWHM. A set of Si drift detectors and bent Laue crystal analyzers may be used in combination with standard ionization chambers for X-ray fluorescence measurements. BioCAT's scanning software allows fast continuous scans to be performed while acquiring and storing full multichannel analyzer spectra per pixel on-the-fly with minimal overhead time (<20 ms per pixel). Together, the high-flux X-ray microbeam and the rapid-scanning capabilities of the BioCAT beamline allow the collection of XFM and micro X-ray absorption spectroscopy (microXAS) measurements from as many as 48 tissue sections per day. This paper reports the commissioning results of the new instrument with representative XFM and microXAS results from tissue samples.
authors.affiliation: The Biophysics Collaborative Access Team (BioCAT), Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL 60616, USA. rbarrea@iit.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Barrea
authors.forename: D
authors.initials: D
authors.lastname: Gore
authors.forename: N
authors.initials: N
authors.lastname: Kujala
authors.forename: C
authors.initials: C
authors.lastname: Karanfil
authors.forename: S
authors.initials: S
authors.lastname: Kozyrenko
authors.forename: R
authors.initials: R
authors.lastname: Heurich
authors.forename: M
authors.initials: M
authors.lastname: Vukonich
authors.forename: R
authors.initials: R
authors.lastname: Huang
authors.forename: T
authors.initials: T
authors.lastname: Paunesku
authors.forename: G
authors.initials: G
authors.lastname: Woloschak
authors.forename: T C
authors.initials: TC
authors.lastname: Irving
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000737:chemistry; D004867:Equipment Design; D005260:Female; D006801:Humans; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008297:Male; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D011467:Prostate / Q000737:chemistry; D011471:Prostatic Neoplasms / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission / Q000295:instrumentation / Q000379:methods*; D017356:Synchrotrons / Q000295:instrumentation*; D014015:Tissue Banks; D056928:X-Ray Absorption Spectroscopy / Q000295:instrumentation / Q000379:methods; D014961:X-Ray Diffraction / Q000295:instrumentation