Biological imaging by soft x-ray diffraction microscopy

doi:10.1073/pnas.0503305102

Biological imaging by soft x-ray diffraction microscopy

^*Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800; ^†Department of Physics, Cornell University, Ithaca, NY 14853; ^§Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; ^∥Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215; and ^‡Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973

Edited by Margaret M. Murnane, University of Colorado, Boulder, CO (received for review April 21, 2005)

Abstract

We have used the method of x-ray diffraction microscopy to image the complex-valued exit wave of an intact and unstained yeast cell. The images of the freeze-dried cell, obtained by using 750-eV x-rays from different angular orientations, portray several of the cell's major internal components to 30-nm resolution. The good agreement among the independently recovered structures demonstrates the accuracy of the imaging technique. To obtain the best possible reconstructions, we have implemented procedures for handling noisy and incomplete diffraction data, and we propose a method for determining the reconstructed resolution. This work represents a previously uncharacterized application of x-ray diffraction microscopy to a specimen of this complexity and provides confidence in the feasibility of the ultimate goal of imaging biological specimens at 10-nm resolution in three dimensions.

Footnotes

↵ ¶ To whom correspondence should be sent at the ^* address. E-mail: chris.jacobsen{at}stonybrook.edu.
Author contributions: D. Shapiro, T.B., V.E., M.H., C.J., J.K., E.L., and D. Sayre designed research; D. Shapiro, P.T., T.B., V.E., M.H., C.J., J.K., E.L., H.M., and A.M.N. performed research; D. Shapiro, P.T., V.E., C.J., E.L., H.M., and A.M.N. analyzed data; D. Shapiro, P.T., T.B., V.E., M.H., C.J., and E.L. contributed new reagents/analytic tools; and D. Shapiro, V.E., M.H., C.J., J.K., and D. Sayre wrote the paper.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations: XDM, x-ray diffraction microscopy; CCD, charge-coupled device; STXM, scanning transmission x-ray microscope.
Freely available online through the PNAS open access option.