Welcome to IVF
Welcome to IVF
Welcome to IVF
-How is FISH analysis done?
Commercially available DNA probes labeled with different fluorescent dyes are hybridized to the nucleii of cells, and analyzed under a fluorescence microscope. If the probe for chromosome 21 is labeled with an orange fluorescent dye, for example, we will see 2 orange signals under a fluorescence microscope in normal cells, and 3 orange signals in cells of a patient with Down syndrome (Trisomy 21). The diagnosis is thus made by counting the number of signals of different colours in each cell. The cells are counterstained with a blue dye DAPI, to differentiate the nucleii.