title: Fluorescence in situ hybridization (FISH) as a method to detect aneuploid cells.
abstract: OBJECTIVE
  To test the sensitivity and specificity of various FISH probes for detecting male and aneuploid cells and to determine the percentage of fetal cells that must be present in a sample in order to use the probes for prenatal diagnosis.
  
  
  METHODS
  Adult human lymphocytes were cultured and harvested. Twelve different proportions of male to female cells and 5 different proportions of trisomy 21 cells and trisomy 18 cells in euploid cells were prepared for FISH. Alpha-satellite DYZ1 was applied to detect the male cells. Chromosome 21/Down syndrome critical region cosmid and D13Z1/D21Z1 alpha-satellite probes were applied to detect trisomy 21 cells. The D18Z1 alpha-satellite probe was used to detect trisomy 18 cells.
  
  
  RESULTS
  DYZ1 detected male cells reliably in concentrations as low as 2%. Both D18Z1 and chromosome 21/Down syndrome critical region cosmid probes could detect aneuploid cells at reasonably achievable concentrations. However, the D13Z1/D21Z1 probe was not sensitive below concentrations of 50%.
  
  
  CONCLUSIONS
  FISH is an alternative technique for noninvasive prenatal diagnosis. The sensitivity and specificity of FISH probes may play a crucial role in the accuracy of prenatal diagnosis.
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Medical College Hospital, Taiwan.
authors.forename: H J
authors.initials: HJ
authors.lastname: Wei
authors.forename: T H
authors.initials: TH
authors.lastname: Su
authors.forename: C L
authors.initials: CL
authors.lastname: Chien
authors.forename: C R
authors.initials: CR
authors.lastname: Tzeng
mesh_terms: D000328:Adult; D000782:Aneuploidy; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D018895:Microsatellite Repeats; D012680:Sensitivity and Specificity; D014314:Trisomy / Q000235:genetics*