title: A microfabricated fixed path length silicon sample holder improves background subtraction for cryoSAXS.
abstract: The application of small-angle X-ray scattering (SAXS) for high-throughput characterization of biological macromolecules in solution is limited by radiation damage. By cryocooling samples, radiation damage and required sample volumes can be reduced by orders of magnitude. However, the challenges of reproducibly creating the identically sized vitrified samples necessary for conventional background subtraction limit the widespread adoption of this method. Fixed path length silicon sample holders for cryoSAXS have been microfabricated to address these challenges. They have low background scattering and X-ray absorption, require only 640 nl of sample, and allow reproducible sample cooling. Data collected in the sample holders from a nominal illuminated sample volume of 2.5 nl are reproducible down toq≃ 0.02 Å-1, agree with previous cryoSAXS work and are of sufficient quality for reconstructions that match measured crystal structures. These sample holders thus allow faster, more routine cryoSAXS data collection. Additional development is required to reduce sample fracturing and improve data quality at lowq.
authors.affiliation: Laboratory of Atomic and Solid State Physics, Cornell University , Ithaca, New York 14853, USA.
authors.forename: Jesse B
authors.initials: JB
authors.lastname: Hopkins
authors.affiliation: School of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, USA.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Katz
authors.affiliation: School of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, USA.
authors.forename: Steve P
authors.initials: SP
authors.lastname: Meisburger
authors.affiliation: Laboratory of Atomic and Solid State Physics, Cornell University , Ithaca, New York 14853, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Warkentin
authors.affiliation: Laboratory of Atomic and Solid State Physics, Cornell University , Ithaca, New York 14853, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Thorne
authors.affiliation: School of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, USA.
authors.forename: Lois
authors.initials: L
authors.lastname: Pollack
keywords: 100 K; biological small-angle X-ray scattering; cryoSAXS; fixed path length; sample holders; solution scattering