In vivo X-ray elemental imaging of single cell model organisms manipulated by laser-based optical tweezers

Over the past years, GhEnToxLab has developed an active and fascinating collaboration with the UGhent’s X-ray Microspectroscopy and Imaging Group (XMI). This lab, led by Prof. dr. Laszlo Vincze, is specialized in the development of synchotron radiation-based tools for micro X-ray imaging, absorption spectroscopy and fluorescence analysis. Among other techniques, they are currently developing a method that uses lasers to trap and manipulate single celled organisms in their native environment. The optically trapped organism can then be subjected to micro X-ray fluorescence imaging, providing us with a radically new tool to map the subcellular elemental composition of these cells. This method was first used and developed at the European Synchotron Radiation Facility (ESRF) to map the cellular distribution of Cu & Ni in a metal exposed marine dinoflagellate (Scrippsiella trochoidea). More information on this exciting technique as well as the key findings of these experiments can be found in the first joint scientific paper.

Scientific abstract

We report on a radically new elemental imaging approach for the analysis of biological model organisms and single cells in their natural, in vivo state. The methodology combines optical tweezers (OT) technology for non-contact, laser-based sample manipulation with synchrotron radiation confocal X-ray fluorescence (XRF) microimaging for the first time. The main objective of this work is to establish a new method for in vivo elemental imaging in a two-dimensional (2D) projection mode in free-standing biological microorganisms or single cells, present in their aqueous environment. Using the model organism Scrippsiella trochoidea, a first proof of principle experiment at beamline ID13 of the European Synchrotron Radiation Facility (ESRF) demonstrates the feasibility of the OT XRF methodology, which is applied to study mixture toxicity of Cu-Ni and Cu-Zn as a result of elevated exposure. We expect that the new OT XRF methodology will significantly contribute to the new trend of investigating microorganisms at the cellular level with added in vivo capability.

Full reference (link)

Vergucht, E., Brans, T., Beunis, F., Garrevoet, J., De Rijcke, M., Bauters, S., Deruytter, D., Vandegehuchte, M., Van Nieuwenhove, I., Janssen, C., Burghammer, M., Vincze, L., 2015. In vivo X-ray elemental imaging of single cell model organisms manipulated by laser-based optical tweezers. Sci. Rep. 5. 9049.