title: X-ray diffraction from intact tau aggregates in human brain tissue.
abstract: We describe an instrument to record x-ray diffraction patterns from diseased regions of human brain tissue by combining an in-line visible light fluorescence microscope with an x-ray diffraction microprobe. We use thiazine red fluorescence to specifically label and detect the filamentous tau protein pathology associated with Pick's disease, as several labs have done previously. We demonstrate that thiazine red-enhanced regions within the tissue show periodic structure in x-ray diffraction that is not observed in healthy tissue. One observed periodicity (4.2 Å) is characteristic of cross-beta sheet structure, consistent with previous results from powder diffraction studies performed on purified, dried tau protein.
authors.affiliation: DePaul University, Department of Physics, 2219 N. Kenmore Ave., Chicago, IL 60614.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Landahl
authors.forename: Olga
authors.initials: O
authors.lastname: Antipova
authors.forename: Angela
authors.initials: A
authors.lastname: Bongaarts
authors.forename: Raul
authors.initials: R
authors.lastname: Barrea
authors.forename: Robert
authors.initials: R
authors.lastname: Berry
authors.forename: Lester I
authors.initials: LI
authors.lastname: Binder
authors.forename: Thomas
authors.initials: T
authors.lastname: Irving
authors.forename: Joseph
authors.initials: J
authors.lastname: Orgel
authors.forename: Laurel
authors.initials: L
authors.lastname: Vana
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Rice