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FISH analysis for Chronic Eosinophilic Leukaemia

Test Background

FISH: FISH involves the application of DNA probes specific to genes or genetic regions of interest and attached to the probes are fluorescent molecules which confirm the presence or absence of a particular genetic aberration when viewed under fluorescence microscopy.

Clinical Indications

Myeloid neoplasms associated with eosinophilia and rearrangement of FIP1L1-CHIC2-PDGFRA, PDGFRB, and FGFR1 supports the diagnosis of chronic eosinophilic leukaemia (CEL)/(HES) in patients with chronic hyper eosinophilia.

FIPLI::PDGFRA M85.7

PDGFRB M85.26

FGFR1 M85.27

JAK2 M85.28

BCR::ABL1 M85.24 by request

Reference Range

N/A

Sample volume
Please see: Sample & Container Required
Turnaround time
HES/CEL referrals are treated as routine; 95% should be reported within 21 calendar days.
Sample & Container Required
3mls Bone marrow in lithium heparin. 5mls peripheral blood in lithium heparin (if disease cells are present in sufficient numbers to allow cell culture and/or FISH studies, as appropriate)

EDTA PB and BM samples (1ml) are acceptable for FISH only studies as appropriate. Please note the laboratory does not provide transport medium. Samples sent in transport media from an external laboratory containing Lithium heparin will be accepted if no other media available

Other fresh tissues can be analysed by FISH e.g. ascitic fluid or CSF have no specific volume requirements but should be collected into a preservative free container.

For all samples lower volumes may be accepted and processed.
Notes

If the blood counts are abnormal (high or low white cell count) the volumes of BM/PB requested can be adjusted accordingly. For culture (karyotyping) a WCC of 5×10^6 cells per ml is optimal.

Delayed Samples
Samples should arrive in the laboratory as soon as possible after sampling (ideally within 24 hours). Sample will not be rejected if >72 hours delayed in transit but may yield poor quality or failed results. If a delay in sample transportation is anticipated, samples should be refrigerated (4°C) and dispatched as soon as possible on the next working day.

Record last updated
November 19, 2025

Sample Container

6ml Lithium Heparin (Green top)

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Test Results

Yes, we have a Pathology User Guide

Yes. Please email your request to Imperial.nwlpcustomerservice@nhs.net

Results are communicated to clinical staff and are normally not communicated direct to patients either on telephone requests or in written report. If you need to contact us please click here to view the contact details page

Please contact the Customer Service Team Monday to Friday from 8:30am – 6:00pm on 0203 313 5353. Alternatively, see the Pathology User Guide for how to contact the relevant department. If advice is not urgent you can also email your query to Imperial.nwlpcustomerservice@nhs.net

Additional tests may be added by discussion with the relevant laboratory. The time limit for adding additional tests to a sample already received in the laboratory will depend on the type of sample and the department it was sent to.

Information on the repertoire of tests performed by pathology, including reference ranges, turnaround times and specimen requirements, can be found in the test directory.

NWLP operates UKAS accredited medical laboratories as per the references below. The current scope of accreditation for all NWLP’s laboratories can be found on the UKAS website.

See the following UKAS ref numbers:

  • Clinical Biochemistry Ref: 8673
  • Haematology and Blood Transfusion Ref: 8674
  • Infection & Immunity Sciences (Including Immunology, Virology, Microbiology and Histocompatibility and Immunogenetics ) Ref: 8659
  • Cellular Pathology (Including Histopathology, Cytology and Molecular Pathology) Ref: 9615

If you require copies of our certificate of accreditation and associated documentation please contact Imperial.nwlpcustomerservice@nhs.net.

UKAS requires the laboratories to be accredited for a particular repertoire/scope (ISO15189), any changes or additions to repertoire require assessment by UKAS (extension to scope).

The BD Hospital Tube GuideBD GP Tube Guide and BD Paediatric Tube Guide provide visual references to the correct tube types and collection instructions.

Home testing

INSTRUCTION SHEET FOR BLOOD SAMPLE COLLECTION 

We also have two instruction videos available (one with subtitles and one without) – please click on the links to view the videos on Google.

VIDEO ON BLOOD SAMPLE COLLECTION (without subtitles)

VIDEO ON BLOOD SAMPLE COLLECTION (with subtitles)

Our accreditations

Upholding excellence in diagnostic standards

Our laboratories are accredited by the UK Accreditation Service (UKAS) against the international standard ISO15189:2022. UKAS is the accreditation body for the UK that assesses medical laboratories.

Find out more about our accreditations on the UKAS website.

UKAS website
Man in the lab handling a sample