Microbeam

In cooperation with the Materials Research group the existing microbeam facility was optimized for the irradiation of biological samples. Individual single cells with fluorescently stained cell nuclei can be automatically detected, positioned and irradiated. The precision of the position of individual ion hits is in the order of 1μm, and individual cells or cell nuclei can be irradiated with a predefined number of ions. The image below shows an example for the high precision of the beam delivery system. Therefore, a geometrical pattern representing the letters "GSI" was delivered in a single cell nucleus (diameter approximately 15μm).

The cell nucleus is stained with a red fluorescent dye and detected by confocal laser scanning microscopy. The positions of ion traversals are visualized by means of the corresponding biological response of the cell to the radiation damage. Therefore, a protein involved in DNA damage repair was stained, which accumulates at the position of particle traversals (yellow spots); the yellow circles indicate the targeted position. Each position was irradiated with four low energy helium ions.

Relevant publications:

Barberet, P., Fournier, C., Knauf, F., Heiss, M., Fischer, B. E. and Taucher-Scholz, G.
Studies on the induction of the cell cycle regulator CDKN1A (p21) in bystander cells using the GSI heavy ion microbeam (Proceedings).
Radiat. Res. 2006, 166 :682-684.

Fournier, C., Becker, D., Heiss, M., Barberet, P., Winter, M. and Taucher-Scholz, G.
Cell cycle-related bystander responses are not increased with LET following heavy ion irradiation
Radiat. Res. 2007, 167: 194-206
  

contact: Claudia Fournier