National Center for X-Ray Tomography

National Center for X-Ray Tomography

Research Emphasis

Current Research

The National Center for X-ray Tomography (NCXT) is developing instrumentation and methodology for three-dimensional (3-D) imaging of whole cells up to 10 microns thick. The wavelength of the X-rays used (2.4 nm) makes it possible to achieve better resolution than can be obtained with light microscopy, up to 20 nm with the present optics. Biological material is examined at atmospheric pressure and can be fully hydrated and imaged in its native state. Since organic material absorbs approximately an order of magnitude more strongly than does water at this wavelength, structural details of cells are easily observed without the need for contrast enhancement reagents. Collection of tomographic datasets is fully automated and can be accomplished in less than three minutes, revealing 3-D images of structures throughout the entire cell. Immunolabeling techniques are being developed for 3-D localization of molecules in whole cells. Methods are being developed for high-throughput imaging of dynamic events in live cells using light microscopy and high-resolution analyses of those same cells using X-ray tomography

Resource Capabilities

Instruments

The NCXT is building a state-of-the-art X-ray microscope dedicated to biological X-ray microscopy and, until completed, is using the soft X-ray microscope operated by the Center for X-ray Optics located at the Advanced Light Source. A fully equipped biological laboratory is available and contains a dedicated cell/tissue culture room and all associated equipment. Rapid freezing devices are also available, including a propane-jet freezer and ethane plunge freezer. Several light microscopes are available, including a Zeiss 510 NLO laser scanning confocal and multiphoton imaging system, a Bio-Rad 1024 confocal microscope, and digital camera-based upright light microscopes. PC and Macintosh computers are available for image processing using Imod, Spider, Image Pro Plus, Amira, and other commercially available programs.