flow cytometric multicolor analyser

Flow cytometry provides an unequalled technique for the analysis of rare cell types in the context of larger populations of cells. Combined use of defined flow cytometric reagents not only allows to identify minute numbers of specific cells in a total population but also enables to elucidate key aspects of their biological function. Moreover, flow cytometric cell sorting techniques, up to the level of single cell sorting, permit further investigation and modulation of specific cell populations for scientific or clinical purposes under experimentally defined conditions. The technique of flow cytometry in combination with the vastly expanded availability of defined monoclonal antibodies has been instrumental in identifying and investigating multipotent cell populations that are able to generate differentiated offspring and thus to the "demystification" of stem cell research.In the current grant proposal we apply for an advanced multicolor flow cytometer which is indispensable for a number of research lines dedicated to fundamental aspects of stem cell biology. This includes the identification of candidate stem cell populations, analysis of their proliferative and homing properties, and the ability to grow stem cells in vitro. In addition, understanding stem cell biology requires extensive knowledge of the activity of stem cell signal transduction. Flow cytometry is the only available technique capable of performing this kind of analysis on a single cell basis (Cell, 2004; 118: 217-28) and the advent of single cell profiling of phospho-protein networks, especially of stemcells, is critically dependent on the acquisition of a state of the art flow cytometer. Also, in a number of translational research lines this equipment is vitally needed to investigate ABC transporter mediated drug efflux capacity and inherent resistance towards genotoxic stress of malignant precursor cells from AML patients. Finally, the equipment will make a decisive contribution to research aimed at the characterization of tissue damage evoking mobilisation of stem cells and their therapeutic exploitment for tissue repair.Since flow cytometry is a technique employed by many researchers, The Faculty of Medical Sciences of the University of Groningen has stationed the available flow cytometry equipment in a core facility known as the Central Flow cytometry Unit (CFU). The significant demand for high quality analytical work is made possible by the appointment of two flowcytometry operators, who supervise and handle the equipment on a daily basis. The overall supervision over the CFU is held by a "flow cytometry administration committee", comprising the group-leaders of the most regular flow cytometer user-group.The research lines touched upon in the above and elaborated on in this proposal, require a flow cytometry utility which allows to combine 3+ color phenotyping with functional monitoring of cell biological characteristics. Importantly, the research questions can not be addressed using one of the flow cytometers currently present in the CFU. Our current multi-color analyser, a Coulter-Elite, neither is equiped for 3+ color analysis nor shows the sensitivity of detection needed for a number of the analytical procedures. With the purchase of a state of the art multicolor flowcytometer (LSR-II by BD Biosciences), an important prerequisite will be met to bring stem cell research to a next phase.