Strike action will be taking place from 7am Saturday 24 February 2024 to Thursday 28 February 2024. Please continue to attend your appointments unless you are contacted and told otherwise.

The strike action may mean our A&E is a lot busier than usual, which means the waiting times will be longer. If you need help which is not life threatening, please use 111, Pharmacies, GPs or Urgent Treatment Centres. Thank you for your understanding during this period.

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Solid Tissues

Sample requirements

Skin, placental material or products of conception

Samples should be referred in sterile isotonic saline in a sterile universal or other sealed sterile container. Fresh samples should ideally be sent to the Cytogenetics Department on the same day. Where a delay is inevitable (such as over weekends) please store the sample in a refrigerator. Please note that we cannot process samples that have been exposed to formalin.

Please avoid using large containers or sending large quantities of liquid. Ensure all containers can be securely sealed (preferably screw caps) and are appropriately packaged (see packaging guide) and that the referral form is separated from the container by a waterproof layer in case of leakage during transport.

 

Effusion or ascitic fluid

Samples should be referred in a sterile universal or other sealed sterile container.

 

Buccal smears

Samples should be applied to poly-l-lysine coated slides. Please contact the department before testing to discuss the test required. These samples can only be processed for targeted FISH.

 

Acceptance Criteria

In order to target limited resources, for this group of referrals the Cytogenetics Department operates an acceptance policy, please see below. For referrals which do not fulfil these criteria please contact the laboratory to discuss the test you require.

Referral categories:

  • Patients with recurrent pregnancy loss (2 or more previous pregnancy losses i.e. this is at least the third pregnancy loss or subsequent) (R318)
  • Fetus with a likely chromosomal abnormality detected on scan or after delivery, should be used in:
  • Cases of isolated miscarriage with additional features suggestive of chromosome abnormality
  • IUFD/stillbirth (if indication of foetal abnormality with a likely genetic cause at first or second trimester)
  • Fetal anomalies with a likely genetic cause.
  • Other testing criteria include:
  • ·              Cases of third trimester intrauterine death or still birth in the absences of other likely causes.
  • ·              Congenital malformation and dysmorphism syndromes
  • ·              Family known to carry a chromosome abnormality
  • ·              Confirmation of an abnormal prenatal test.
  • ·              Sample from live patient to screen for mosaicism
  • ·              Fibroblast cultures requested. Skin fibroblast sample requiring culture and storage for potential future testing, or forwarding for biochemical testing. See below.

Tests

Microarray

Fetal skins, placenta and products of conception material will usually be processed by microarray for identification of genetic imbalance over 1Mb in size, unless otherwise indicated. In addition this test will identify triploidy and true molar pregnancies. If possible mosaicism is indicated in the referral, cultures may be established as well as DNA extracted for microarray testing. Please indicate clearly on the referral card if mosaicism is suspected, if there is a suspected fetal abnormality or if DNA storage is required.

 

Targeted FISH

We also offer a targeted FISH test where appropriate.

 

Fibroblasts

Skin samples can be sent to the Cytogenetics Department to establish fibroblast cultures which can then be forwarded for biochemical assays, molecular tests or for DNA extraction/storage. Samples for these referrals should be of full thickness. These skin samples should be accompanied by a letter to the appropriate testing centre to which cultures are to be forwarded. The letter should also include the test required and the name and address of the requesting clinician.

 

Reporting times

If you have a specific request for a result urgently, please contact the laboratory.

Please see our Target Reporting Times.

 

Limitations

Please see our limitations of tests page.

Storage and further testing

DNA from samples referred for microarray testing is stored indefinitely. Any stored tissue from archived samples (i.e. products of conception or fetal tissue that do not meet the criteria but are stored due to sensitivity and unrepeatable nature of these samples) will be kept for 1 year for possible DNA extraction if required. Reactivation of these samples are required to be in writing, either by sending a new referral form to the department clearly marking it as a reactivation of a sample held in the laboratory or by email with 3 patient identifiers. Please include the reason for reactivation. 

Successful fibroblast cultures are available for 1 month after primary cultures have been forwarded as appropriate. Fixed material from samples that had been cultured for previous karyotype analysis or fixed material for FISH is stored for at least 10 years for cases with an abnormal karyotype.

Page last updated 20/09/2023. Please note that if printed, the information is only valid on the day of printing.