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FISH analysis for B Lymphobasticleukaemia/lymphoma

Category Specialist Integrated Haematological Malignancy Diagnostic Service (SIHMDS) >> Cytogenetics
Test background

FISH involves the application of fluorescent DNA probes specific to genes or genetic regions of interest that highlight abnormalities involving these regions.

Clinical Indications

Although acute lymphoblastic leukemia (ALL) is often considered a paediatric disease, nearly half of newly diagnosed ALL occurs in patients older than age 20. There are recurrent genomic findings that define the classification of ALL. Cytogenetic and FISH testing is delivered in line with the National Genomic Test Directory (NGTD) for Cancer.

A rapid FISH panel is performed on all diagnostic B-ALL cases and is reported within 3 calendar days.

Reference range


Sample & container required See notes section
Sample volume Samples would not be rejected on the basis of small volume, however, 5 mL is ideal.
Turnaround time See notes section

Sample required:

Bone marrow in cytogenetic transport medium (preferred) or lithium heparin is usually the sample of choice, but peripheral blood in lithium heparin may be suitable if there are circulating blasts and/or a high white blood cell count. EDTA samples are only suitable in cases requiring FISH only (ie follow-up samples from patients with FISH-detectable abnormalities, or blood samples taken at diagnosis for exclusion of a specific gene fusion when a bone marrow sample will shortly follow). If in doubt please use lithium heparin. Samples which are non-sterile, clotted or collected in sodium citrate, fixative or saline are not suitable. To ensure appropriate analysis and interpretation it is important to provide clear and concise clinical information.

Turnaround times:

  • Rapid FISH tests 3 calendar days
  • Urgent FISH/Karyotype: 95% should be reported within 14 calendar days
  • Post treatment follow-up samples are treated as routine; 95% should be reported within 21 calendar days