Biological imaging by soft x-ray diffraction microscopy

TLDR

The study aims to achieve optimal reconstructions of yeast cells by handling noisy, incomplete diffraction data and determining resolution, thereby demonstrating the feasibility of 10‑nm 3‑D imaging of biological specimens. The authors employed 750‑eV x‑ray diffraction microscopy on intact, unstained yeast cells, collecting data from multiple angles and applying noise‑handling procedures and a resolution‑determination method to reconstruct the complex exit wave. The reconstructions revealed several major internal components at 30‑nm resolution, with excellent agreement among independently recovered structures, confirming the accuracy of the technique and supporting the feasibility of 10‑nm 3‑D imaging.

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.