The Application Of Fluorescent In Situ Hybridization(fish)in Prenatal Diagnosis

Objective: To study the fluorescent in situ hybridization (FISH) in prenatal diagnosis, try to analyze the clinical application and quality control of FISH protocol. Methods: The interphase nuclei of amniotic fluid from 189 pregnant women with 16～24 gestational weeks, umbilical cord blood from 32 pregnant women with 25～32 gestational weeks and chorionic villus from 5 pregnant women with 9～12 gestational weeks were detected by chromosome-specific DNA probes which consist of the chromosome number detection probes(13, 18, 21, X and Y chromosomes) and chromosomal microdeletion probe(22q22.1 microdeletion syndrome). The routine karyotypes analysis was performed at the same time. based On the good command of FISH protocol and literature reviewing, we try to improve the FISH protocol on sample digestion, probe hybridization and slide washing to set up the FISH technology prenatal diagnosis Platforms.Results: The FISH diagnosis of all 226 species was achieved in 24~48h, while 224 chromosome karyotypes diagnosis acquired in 3 weeks, since failed cell culture occurred in 2 amniotic fluid cases. The success rate of FISH diagnosis is 100%, while the karyotypes diagnosis success rate is 99.1%. Chromosome aneuploidies were found in 4 cases through both the two methods. 7 chromosomal structural abnormality were found in chromosome karyotypes analysis while 1 chromosomal structural abnormal case was found in FISH diagnosis, since the remaining abnormal cases were beyond the FISH diagnosis. So, for the two methods, the diagnosis of all cases matched perfectly. Through the discussion of FISH protocol, we optimized the FISH experimental procedure, shortened the time of diagnosis time and set up the FISH technology prenatal diagnosis Platforms.Conclusion: The FISH technology could release the report in 24~48h , which would ease the anxiety of the pregnant women and their family members. Moreover, it can be applied in a wide range of samples tested. So, The improved FISH technology holds an important clinical value for its efficient, time-saving and wide range of samples tested.