The lab of molecular cytogenetics at the Institut für Humangenetik in Jena has different research lines, all of them connected by the interest in chromosome structure and evolution. The main research interest is within the frame of clinical genetic research, i.e. the characterization of acquired and inherited chromosomal aberrations with the aim to understand the biological background of how and why such alterations from the normal happen. There are ongoing projects on small supernumerary marker chromosomes (http://ssmc-tl.com/sSMC.html), chromosomal heteromorphisms on chromosomes 2 and 9 and fragile sites. In leukemia-research the lab is involved in the search for cryptic, disease-associated or -causing chromosomal aberrations. Besides we are interested in chromosomal evolution and have cowork with other groups working on fish-species (Brasil), turtle (Italy), or Rhodentia (Russia). Apart from multicolor fluorescence in situ hybridization (http://ssmc-tl.com/mfish.html) approaches like immunohistochemistry, microsatellite analysis (http://upd-tl.com/upd.html) or array-CGH are applied in the research.