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Solid tissues

Solid Tissues

Sample requirements

Skin, placental tissue 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 unavoidable (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 sent 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

Samples can only be accepted for analysis if referral criteria set out in the National Genomics Testing Laboratory for Rare Disease are met. See below. For referrals which do not fulfil these criteria please contact  the laboratory to discuss the test you require.

  • 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
  • Intrauterine death or stillbirth at or later than 24 weeks gestation
  • 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 skin, placenta and products of conception 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 most complete 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 clinician to whom the report should be sent.

 

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 referral 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. To activate testing of samples that have been stored but not analysed please email the cytogenetics laboratory stating the reason for analysis (see criteria above) and including three patient identifiers as well as our laboratory reference number.

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

Any tissue that is not required for analysis or storage is forwarded for sensitive disposal after processing.

Page last updated 20/11/2025. Please note that if printed, the information is only valid on the day of printing.