Delivering Science Supporting Healthcare

Chimerism

Test Background

The chimerism investigation is carried out following haematopoietic stem cell transplants to monitor the proportion of host and donor DNA. A semi-quantitative amplification of informative microsatellites in whole blood and T-cell (CD3+) separated samples is undertaken to obtain a value to indicate the donor recipients transplant status.

Purified DNA is amplified via PCR using a set of 15 fluorescent-labelled primer pairs (in one reaction tube multiplex-PCR), specific for amplification of 15 microsatellite markers. Where the amplified products are different sizes (alleles) between donor and host for the same marker, it is possible to discriminate between donor and host DNA. This discrimination of the amount of donor DNA present in the host, thereby providing semi-quantitative data for monitoring level of engraftment.

Click here to download the request form for pre-transplant chimerism tests

Click here to download the request form for post-transplant chimerism tests

Clinical Indications

Allogenic transplant where chimerism knowledge will be informative to patient management [M118.1 (STR)].

Refer to the NHSE National genomic test directory for cancer

Turnaround time
Urgent: 7 calendar days; Non-urgent: 14 calendar days. Note: urgency will be determined by the laboratory based on the clinical information provided on the referral.
Sample & Container Required
4ml peripheral blood or >1ml bone marrow in EDTA, however smaller volumes may be processed. Please note that samples must be received within 72 hours (3 days) of collection for T-cell separation to be performed. Samples must be received to the laboratory before 14:30pm. Any samples received after 14:30pm will be accessioned the next working day and processed according to that date. Please keep samples at room temperature. For other sample types, please liaise with the laboratory.
Notes
Repeat chimerism tests should not be requested until 14 days between tests have elapsed to ensure the result is useful and meaningful in confirming relapse. Early testing may result in misleading results.
For new patients, pre-transplant donor and recipient samples must be provided prior to post-transplant chimerism analysis being undertaken.

Record last updated
November 19, 2025

Sample Container

4ml EDTA Vacutainers (Lavender 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.

UKAS accredited medical laboratory/medical diagnostic service:

  • Clinical Biochemistry No. 8673
  • Haematology and Blood Transfusion No. 8674
  • Infection & Immunity Sciences (Including Immunology, Virology, Microbiology and Histocompatibility and Immunogenetics ) No. 8659
  • Cellular Pathology (Including Histopathology, Cytology and Molecular Pathology) No. 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