Contrast enhancement for in-situ GFP microscopy at the microbeam

In collaboration with GSI Biophysics, the microbeam, operated with ions from the UNILAC linear accelerator of GSI, is routinely employed for targeted irradiation of living cells in culture [1]. A custom-made fluorescence microscope is used both for beam targeting and for cell observation via fluorescent dyes that specifically highlight the biological agent of interest. Green Fluorescent Protein (GFP) is often used to study dynamics of repair proteins shortly after broad-beam ion irradiation in a beamline microscope [2, 3]. A combination of the high-quality in-situ GFP microscopy, currently available at the X6 beamline microscope, with the accurate targeting of single ions performed at the X0microbeam would greatly widen the possibilities of the microbeam for radiobiological studies. Here, we report on technical improvements of the in-situ GFP microscopy setup at the microbeam facility.