Veripath Test Directory

Epic Test Name FISH, TRISOMY 12
Synonyms Trisomy 12 FISH
Chromosome 12 gain, FISH
Description Fluorescence in situ hybridization (FISH) is performed to detect gain of chromosome 12 as seen In chronic lymphocytic leukemia (CLL).
Specimen Requirements 
Container Green top (sodium heparin) collection tube
Specimen Type Bone marrow, blood, tissue
Preferred Collection Volume 2 mL bone marrow,5-10 mL blood, 5mm3 tissue
Minimum Collection Volume
Collection Instructions 1. Bone Marrow: 2 mL aspirated bone marrow preferred) anticoagulated with preservative-free sodium heparin (e.g., greenĀ­ top tube). DO NOT use lithium heparin. Bone marrow biopsy may be submitted if aspirate is not available - see instructions for
Specimen Handling Deliver to lab at room temperature within 24 hours. If collected over a weekend, call the laboratory to make arrangements for specimen delivery. May be refrigerated if not transported immediately. Do not freeze. Protect from heat or cold.
Rejection Criteria Frozen, clotted, hemolyzed or grossly contaminated specimens. Incorrect anticoagulant used. Frozen or fixed tissue specimens, or tissue specimens sent without tissue culture medium.
Methodology A fluorescentlabeled DNA probe for the centromere of chromosome 12
(D12Z1) Is hybridized to unstained Interphase nuclei on a slide. 200 cells are evaluated to determine whether 2 signals are present (normal) or more than 2 signals are present (gain of chromosome 12).
Reference Range
CPT Code(s) 88271, 88275, 88291
Department Cytogenetics
Contact Information (214) 648-0975 or (214) 645-7057 or Toll free: (877)-887-8136
Turn Around Time1-3 days
Performed Sunday - Saturday
Performed by Cytogenetics
Notes Conventional cytogenetic analysis should be performed in addition
to FISH at Initial diagnosis
Updated/Reviewed 12/12/2016