Postnatal Fluorescence in situ Hybridization (FISH) Testing

FISH testing is a molecular cytogenetic analysis that identifies specific chromosomal abnormalities by evaluating the presence or absence of fluorescence labeled signals in metaphase chromosomes or interphase nuclei. FISH results for rapid diagnosis of aneuploidy are typically provided within 24-48 hours from the receipt of the specimen.
 
 
 
 
 
 
 

Specimen Requirements

Postnatal And Adult Karyotyping FISH
Specimen Types Requirements Turnaround Times
Peripheral Blood 1 green top tube (1 x NaHep) containing 5 cc whole blood

For infant or young children: 1 green top tube (1 x NaHep ) containing 1-3 cc whole blood If CGH testing is anticipated later 1 purple top tube (1 x EDTA vacutainer) containing 5cc whole blood is requested
>2-4 weeks for routine cases

48 hr. verbal preliminary results on STAT analyses; 7 day final report on STAT analyses
Postnatal And Adult (CGH or CGH+SNP, FISH and Karyotyping)
Specimen Types Requirements Turnaround Times
Peripheral Blood 1 green top tube (1 x NaHep) and one purple top tube (1XEDTA), each containing 5 cc whole blood

For infant or young children: 1 green top tube (1 x NaHep) and one purple top tube (1XEDTA), each containing -1-3 cc whole blood 1 green top tube (1 x NaHep) containing 5cc whole peripheral blood from each parent
 

Documents

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FISH For aCGH Confirmation

BAC Probes
Whole genomic BAC library is available for aCGH confirmation

Advantages And Limitations

  • FISH testing can rapidly detect and characterize submicroscopic chromosome abnormalities.
  • FISH testing has the ability to analyze the abnormalities on metaphase chromosomes from cultured samples as well as interphase cells from specimens that cannot be cultured.
  • FISH testing has high sensitivity and specificity.
  • The main limitation of FISH analysis is that it only provides information about the specific locus or gene tested.