Genetics counseling Postnatal cytogenetics examination DNA examination FISH Prenatal diagnostics Other examinations Invasive examinations and operations Examination offered in prenatal cytogenetic diagnostics Actions Institute workers Home

FISH The fluorescent in-situ hybridization technique (FISH) is a reliable modern molecular cytogenetics method. A very small quantity of collected biological material is sufficient for performing a goal-directed chromosome examination using FISH and results are available within 24 hours. The technique may be used in both the urgent prenatal area and postnatal diagnostics.       Fish in the prenatal diagnostics serves as fast diagnostic procedure for detection of most common aneuploidies – Down syndrome, Turner syndrome, trisomy of 18^th, 13^th chromosome and inherited translocations. Unlike the standard fetal cell karyotypication by the cultivation method, which takes at least 14 – 18 days, by FISH method, the result can be obtained one day after sampling.  FISH is also used prenatally for detection of marker-chromosome origin, for determination of a number of aberrant cells in mosaics, for diagnostics of microdeletions and various types of structural reconstruction.      In postnatal samples, using FISH, we most often examine structural chromosome reconstruction, especially translocations and microdeletions in some syndromes. The method can be used for a wide range of biological material. At our institute, FISH is carried out mostly prenatally on inter-phase staining (L-FISH) from native, freshly collected amniotic fluid (PV), on chorionic villi (CVS), on fetal lymphocytes during umbilical cord blood collection and on cultivated fibroblast of various origin. Postnatally we examine non-cultivated as well as cultivated peripheral lymphocytes, incisions of cry preserved tissues or paraffin blocks and fixed oocytes and blastomeras within commencement of the pre-implantation genetic diagnostics (PGD).