Das Bild zeigt rechts ein Trichterglas mit blauer Flüssigkeit und Glasstab zum Umrühren. Daneben steht ein Reagenzglasständer mit Reagenzgläsern, die ebenfalls blaue Flüssigkeit enthalten. Im Hintergrund ist ein Forscher zu sehen, der in der rechten Hand eine Pipette hält.

Cytogenetic Diagnostics

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Cytogenetic Diagnostics

Cytogenetic Analyses

In cytogenetic analyses the chromosomes of certain body cells are examined under a light microscope. Aim of this investigation is the proof or exclusion of a numeric or structural conspicuous set of chromosomes (karyotype).

Conventional Cytogenetics

A conventional cytogenetic analyses consists of a production of metaphase preparations which contain cultures of patient cells and a following numeric and structural analyses of chromosomes according to a differential chromosome banding techniques. The most common differential chromosome banding technique is the GTG-banding, which allows a unique identification of each pair of chromosomes as well as a fine structure analyses. This method makes a chromosomal aberrations with relatively low resolution (ca. 10Mb) possible. The sortet presentation of chromosomes according to a differential chromosome banding technique is called Karyogram.

Molecular Cytogenetics

Molecular-cytogenetic methods such as the FISH-Analysis (fluorescence in situ hybridisation) allow an investigation of certain chromosomal areas with a distinctly higher resolution. Their application requires a specific diagnosis which is the result of the clinical symptomatology of the patient. Often molecular-cytogenetic analyses are also necessary to characterize or confirm a previously detected aberration. Furthermore molecular-cytogenetic methods allow an analysis on interphase cores. This is advantageous in issues which do not require dividing cells as a precondition. For this the prenatal rapid test in prenatal diagnostics serves as an example.

Array-CGH

Array-CGH constitutes a special case among the molecular-cytogenetic methods. It enables high-resolution investigations of the human genome and is not depending on proliferating cells. It is only possible to detect genomic profit and loss with Array-CGH. Balanced chromosome aberrations such as translocations and inversions cannot be detected with this method. For a more accurate description see also Array-CGH.

Contact Cytogenetics