Numerous diagnostic questions from many research areas sustain disturbances during analysis, as the analysed cells (“target cells”) often are not only of very marginal occurrence but also surrounded by a lot of other cells (“background cells“). The Research Unit Single Cell Analysis focuses on the analysis of rare cells to develop and apply diagnostic methods of analysis. During the late 1990s, the group of Prof. Dr. Peter Sedlmayr of the Histological Institute of the former Medical Faculty of the Karl Franzens University of Graz started research on non-invasive prenatal diagnostics (NIPD) based on fetal cells circulating in the blood of pregnant women. In this context the research group was part of the network of excellence SAFE (Special Non-Invasive Advances in Foetal and Neonatal Evaluation Network, EU FP6) between 2004 and 2009. Within this scope, Thomas Kroneis worked on his dissertation (1) on single cell analysis, leading to the first publication relevant for the establishment of the Research Unit (2). By proposal of the Head of the former Institute of Cell Biology, Histology and Embryology Prof. Dr. Gottfried Dohr, the Research Unit for Single Cell Analysis was approved by the Rector Prof. Dr. Josef Smolle by 1.5.2010, and DI Dr.Thomas Kroneis became its assigned principle investigator.