Purpose/Objective: The aim of the thesis project is to design and build a sample-holder that is suited for radiobiological experiments on cell and tissue level in Holland PTC. In order to create accurate dose plans for radiobiological experiments, dosimetry and range calculations need to be worked out. Finally the sample-holder is used for the first radiobiological experiment at Holland PTC. Materials and Methods: The sample-holder is constructed as a slab phantom that allows secure and easy positioning of a 6-well cultivating plate, fully made out of polystyrene. Water equivalent thickness (WET) measurements are used to calculate the density of the slabs, which can be used for dose calculations in treatment planning and Monte Carlo software. Radiochromic EBT3 film is used to perform dosimetry during experiments, the films are calibrated using an ionization chamber to be able to perform absolute dosimetry. A 70 MeV single pencil beam is delivered to the sample-holder with EBT3 films in between the slabs to compare a reconstructed Bragg peak from the relative doses of the films with dose calculations performed in RayStation and TOPAS MC. Cell survival experiments with U2OS cells are performed by irradiating with X-rays and protons. Circumstances where such that the influence of cells being on room temperature for several hours and cells being without medium inside the wells during irradiation could be studied. With protons, cells were irradiated both in the plateau region and in the Bragg peak. LETd calculations are performed in TOPAS MC in order to study the RBE-LET relation. Results: The slabs of the phantom are uniform and have a density of either 1.04 g/cm3 or 1.06 g/cm3 Using these density values the range of a 70 MeV can be calculated with a 0.5 mm accuracy using TOPAS MC and RayStation. The relative central axis dose profile calculated with TOPAS was accurate within 5% compared to the measured values with EBT3 film. This was 20\% for calculations with RayStation. Absolute dose measurements with EBT3 film inside a RW3 phantom agree within 1\% with the delivered dose according to the ionization chamber. In the polystyrene sample-holder this difference is 11%. For X-ray irradiation, incubated cells were able to form more colonies after irradiation compared to cells that had been on room temperature for four hours. Cells that were irradiated without medium in the well had a higher surviving fraction than cells that had medium in the well. For proton irradiation the results are limited since all cells that received more than 0.91 Gy had died, but from the available data it can be seen that irradiation in the Bragg peak results in more cell death compared to irradiation in the plateau region. In addition to this, cells that had medium in the wells during irradiation formed less colonies than cells that had no medium in the wells, which is consistent with the results after X-ray irradiation. Dose-averaged LET (LET_d) values are calculated at cell depth for proton irradiation in the plateau region and in the Bragg peak and are 1.30 keV/um and 3.78 keV/um respectively. Conclusion: The sample-holder is well defined for use in RayStation and TOPAS MC and range calculations of a 70 MeV pencil beam are accurate within 0.5 mm. Absolute dose values obtained with EBT3 film inside the sample-holder are higher than expected, additional measurements are recommended. Cell survival experiments show that there is a difference in irradiating cells that are in medium vs cells that are not in medium and that long exposure to room temperature increases cell death after irradiation. Radiobiological experiments should be performed with cells that can be prepared and stored on site. The obtained LETd values are comparable with values found in literature. Due to the limited amount of cell survival data after proton irradiation, not link between RBE and LET can be studied.