Solid tissues
Solid Tissues
Sample requirements
Skin, placental material or products of conception
Samples should be sent 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 (two or more previous pregnancy losses i.e. this is at least the third pregnancy loss)
• Where there has been fetal loss, termination of pregnancy or miscarriage, accompanied by additional features suggestive of a chromosome abnormality
• Third trimester intrauterine death or stillbirth in the absence of other likely causes
• Known familial chromosome abnormality
• Sample from a living patient to screen for mosaicism
• Skin sample for fibroblast culture for further testing or storage. See below.
Tests
Microarray
Fetal skins, placenta and products of conception material will usually be processed by SNP array 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 one 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 17/10/2024. Please note that if printed, the information is only valid on the day of printing.