Cells imaged without damage
Three-dimensional renderings of two orthogonal angles: The whole infected red blood cell (blue), with the parasite (red) and the parasite’s digestive vacuole (grey) are illustrated in orthogonal views a) and b). Views c) and d) show the surface renderings of the parasite and the digestive vacuole corresponding to a) and b) respectively.
Cellular imaging is an essential tool for understanding the biological functions that occur in all living organisms. X-rays provide a path to imaging the internal structure of cells without needing to cross-section them, which can often lead to damage of the cell structure. Two of the major barriers to x-rays being applied to x-ray imaging has been the lack of high spatial resolution and the damage that the x-rays can cause after the long exposures needed to form high-quality absorption images. In this work, Dr. Brian Abbey together with colleagues from La Trobe University, developed a new microscopy technique using x-rays which was used to image the 3D internal structure of a eukaryotic cell at nanometre length scales and with a lower dose of radiation than had previously been possible.
Cells were mounted in the laboratory on a special finder grid which enabled them to easily locate them in the x-ray beam. The x-ray measurements were carried out in Chicago at the Advanced Photon Source, part of the Argonne National Laboratory. The lab-based sample preparation and characterisation of cells is crucial as it focuses on the development of new microscopy tools for both the life sciences and the materials sciences. Access to the state-of-the-art facilities available locally at the Melbourne Centre for Nanotechnology continues to enable the development of key breakthroughs in the rapidly developing field of x-ray imaging and analysis.
The range of applications for high-resolution, low dose, x-ray tomography is vast. Removing the need for damaging sectioning of cells and other biological samples means that the fidelity of their internal structure is maintained, providing researchers with better insight and understanding into their structure and function. This information will in turn be used to develop new medicines for example, and to gain a deeper understanding of living organisms.
Work is in progress to image the malaria parasite using this new x-ray tomography technique. Researchers hope to use this information to eventually optimise new approaches to combating this disease. The facilities at MCN are currently being used to design and fabricate new x-ray optics providing even better images of biological samples. They are also exploring new approaches to mounting and finding the samples exploiting a range of nanofabrication techniques. This work is being carried out in conjunction with experimental developments at the Australian Synchrotron which will result in a new capability for high-resolution x-ray microscopy being available within Australia.
You can read more about this project in Whole-cell phase contrast imaging at the nanoscale using Fresnel Coherent Diffractive Imaging Tomography, published in Scientific Reports.