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Laboratory Test Directory

FISH Analysis


Name Method Department Units
FISH Analysis Only Fluorescence in situ hybridization (FISH)
Cell Culture

Specimen Requirements

Whole blood

Container Type Container Size Specimen Volume

Green tube (Sodium heparin), No Gel

10 mL 3 mL-10 mL

Green tube (Sodium heparin), No Gel

3 mL 3 mL-5 mL

Green tube (Sodium heparin), No Gel

3 mL 1 mL-3 mL

Room temperature - 48 hour(s)
Refrigerated - 72 hour(s)

Specimen Preparation

  • Do not centrifuge
  • Do not freeze
  • Keep at room temperature

Reasons for Rejection

  • Wrong collection tube
  • Frozen specimen
  • Centrifuged specimen
  • Serum sample
  • Clotted specimen


Submission of a completed Genetics Test Requisition Form is required -- please specify which syndrome is suspected or which chromosome region/locus/probe should be tested by FISH analysis. If no specific syndrome or chromosome rearrangement is in question, then chromosomal microarray analysis should be ordered instead of FISH analysis (see test code: SNPMA). Call Cytogenetics Lab at (614) 722-5321 with questions or to perform testing on tissue types other than blood sample. If a structural chromosome rearrangement is in question, then high resolution chromosome analysis (test code: PBCS) may be recommended to be performed in conjunction with this FISH analysis.

Collect whole blood sample in sodium heparin tube (dark green-top tube without gel separator). Do NOT use lithium heparin or other types of heparin tubes; check tube for proper heparin type. FISH analysis will be performed on metaphase cells from cultured blood lymphocytes and specific FISH probe required for the study may need to be ordered from an external vendor; therefore, FISH result from this testing typically takes 3 weeks.

This test uses fluorescence in situ hybridization (FISH) probe specific for a chromosome region in question to assess the presence/absence and copy number of the chromosome region in the patient. This FISH analysis is used to test for:

  • Common chromosome microdeletion or microduplication syndromes such as DiGeorge (22q11.2 deletion) syndrome, Williams syndrome, Prader-Willi syndrome, Angelman syndrome, Smith-Magenis syndrome, Miller-Dieker syndrome, Kallmann syndrome, Wolf-Hirschhorn syndrome, Cri-du-Chat syndrome,and steroid sulfatase deficiency (X-linked ichthyosis) STS deletion.
  • Presence or absence of the SRY gene (male sex determining gene) in patients with ambiguous genitalia who had an apparently normal karyotype.
  • Custom FISH analysis is available to evaluate for presence of mosaicism, to further characterize a marker chromosome, to confirm chromosome rearrangements identified on chromosome analysis or microarray analysis (e.g. translocations, inversions, and insertions), and to evaluate for known familial chromosome rearrangements. For familial rearrangement study, a sample from the family who carries the rearrangement may be required to use as a positive control.


Lab Form

CPT Code

  • 88273
  • 88271
  • 88230