[Chromosomal in situ hybridization and interphase cytogenetics in single cell and tissue section preparations: new methods in tumor diagnosis and clinical cytogenetics].

To overcome the shortcomings encountered in classical cytogenetics, a variety of in situ hybridization techniques have been developed enabling metaphase and interphase cytogenetics on routinely processed tissues and cells. These techniques comprise the detection of numerical chromosome aberrations, the delineation or "painting" of whole chromosomes or certain chromosome regions and the visualization of structural chromosome rearrangements in interphase nuclei. Some of these new methods can reliably be applied also on paraffin-embedded tissues, among them the comparative genomic in situ hybridization (CGH) technique suitable for providing a survey of over- or underrepresented genetic material on the chromosomal level even if only tumour DNA is available.