High-resolution x-ray diffraction microscopy of specifically labeled yeast cells.

Area of Science:

• Biophysics
• Microscopy
• Cell Biology

Background:

• X-ray diffraction microscopy offers advantages over other x-ray microscopy techniques, including no lens-imposed radiation dose or resolution limits.
• It enables high-resolution imaging of biological specimens that are too thick for electron microscopy.

Purpose of the Study:

• To achieve the highest resolution x-ray diffraction micrograph of biological specimens to date.
• To demonstrate molecular-specific gold labeling at different cellular depths using wavefield reconstruction.
• To image whole yeast cells using x-ray diffraction microscopy.

Main Methods:

• Utilized x-ray diffraction microscopy at 750 eV photon energy.
• Employed molecular-specific labeling with concanavalin A conjugated to colloidal gold particles.
• Processed yeast specimens using plunge-freezing in liquid ethane and freeze-drying.

Main Results:

• Achieved a record resolution of 11-13 nm for biological specimens via x-ray diffraction microscopy.
• Demonstrated successful labeling of alpha-mannan sugar in Saccharomyces cerevisiae cell walls.
• Showcased through-focus propagation for visualizing labeled molecules at various depths within cells.

Conclusions:

• X-ray diffraction microscopy provides unprecedented resolution for biological imaging.
• This technique facilitates molecular-specific labeling and depth-resolved imaging within cells.
• The method is suitable for whole-cell imaging of preserved biological specimens.