Indications For Fluorescence In Situ Hybridization
Leukemias, lymphomas, other hematopoietic malignancies and various types of solid tumors can frequently be distinguished by specific chromosomal and genetic abnormalities. Interphase FISH does not require cell division. Interphase FISH analysis can be used to identify those specific abnormalities/translocations that are more commonly observed in certain types of cancers. Chromosome analysis must be ordered in conjunction with or prior to FISH testing.
FISH studies are employed to establish the presence of a known or suspected abnormality. This is particularly useful when there are a small number of cells or no dividing cells in the sample for cytogenetic analysis.
Collection Procedure
Refer to specific specimen requirements for fresh bone marrow and peripheral blood
Smear Slides:
- FISH can be performed on unfixed, unstained bone marrow or blood smears; however, a complete study may not be possible. One slide per FISH analysis is preferred
- Air dry. Do not oven dry
- Send slides in protective case to prevent damage
Fixed Paraffin Block:
- Tissue should be fixed-well in formalin
- Do not decalcify
- Prepare 0.2 cm x 0.2 cm x 0.2 cm tissue sections
- Store specimen at room temperature (>16°C)
- Use cold pack for transport. Be sure cold pack is not in direct contact with specimen during transport
Specimen Requirements
FISH analysis is performed following cytogenetic analysis
Specimen Container
Refer to specific specimen requirements for fresh bone marrow and peripheral blood
Methodology
Tissue culture, microscopic analysis, digital image capture and karyotype production
Causes for Rejection
Refer to specific specimen requirements for fresh bone marrow and peripheral blood
Transport
Refer to specific specimen requirements
Turnaround Time
FISH results are provided in 1-3 days or 7-10 days when ordered with cytogenetics
7-10 days for paraffin blocks