Sending Samples to the Laboratory
Referral of samples
For the majority of tests, blood samples are preferred and should be collected in EDTA tubes (2-5ml for adults/children and 1-2ml for neonates). For other types of sample please contact the laboratory (please note that best-practice recommends that a maternal sample should accompany any cord blood or prenatal sample e.g. cvs, amniotic fluid, fetal blood or tissue). Testing for facioscapulohumeral muscular dystrophy, which is sent for testing elsewhere, requires a larger volume of blood - minimum of 8ml in EDTA tube is requested.
For diseases where both Cytogenetic analysis and DNA analysis may be carried out (eg. Fragile X, Prader Willi syndrome and Angelman syndrome) a sample in EDTA is required for DNA analysis and a separate Lithium Heparin is required for cytogenetic analysis (see cytogenetic website for details).
Clotted blood is unsuitable for analysis.
If further testing is required on a sample already stored in the laboratory please request this in writing either by fax, post or email.
Please note: We will not accept lithium heparin samples for molecular genetic analysis. Please see this document for more details.
Sending samples as DNA
For our NGS Services we recommend sending at least 5µg of DNA at a minimum concentration of 50µg/ml.
In line with Leeds Teaching Hospitals Trust policy the minimum identifiers required on a Specimen container for sample acceptance are:
- Full Name (forename and surname)
- One other unique identifier (Date of Birth/Unit No./NHS No.)
All specimen containers must be clearly labelled by hand.
If the specimen container does not have a label, a blank label can be hand written and attached.
PAS (addressograph) labels must not be used.
All demand printed labels must be signed and dated to be acceptable
A fully completed referral card including the identifiers that appear on the sample tube must accompany the sample.
Any Samples that do not meet the above labelling standards (or samples where the information is illegible) may be rejected
In order for a sample to be analysed and reported, we require the following MINIMUM information to be provided in the referral:
- Patient Forename
- Patient Surname
- NHS Number
- 1st Line of Patient Address
- Patient Postcode
- Patient Date of Birth
- Referrer Name (surname and first initial) if not the same as GP
- Referrer Facility
- Hospital Number (if applicable)
- National genomics test directory clinical indication code e.g. R53 Fragile X
- Full clinical details of the patient being tested
- Secure email address for return of reports
The collection of this information is essential and it is the responsibility of the referrer to provide it.
Please note: For non-NHS referrals (private or referrals from outside the UK), it is not necessary to provide the NHS number and GP name/address. For these referrals it is essential that a billing address is included with the referral details. For private or non-NHSE referrals please contact the laboratory for testing costs.
We will NOT perform testing on samples that are referred with incomplete information. Seriously mislabelled samples may be discarded. Other samples will have DNA extracted and stored until missing information is received. This will obviously have a significant impact on the length of time taken to receive test results.
Sample acceptance and consent
It is assumed that when a sample is sent to the laboratory, the clinician responsible for the care of the patient has obtained appropriate and valid consent for testing and storage so that the laboratory is not required to confirm and document such consent.
For more information on consent please see the guidelines from the Joint Committee on Medical Genetics.
Acceptance of a sample and referral card from the referring clinician by the testing laboratory should be considered as an entry into an agreement between both parties.
It is the responsibility of the referring clinician to clearly state on the referral card the test selected. The referring clinician should also include any other information that may affect the interpretation of the result such as clinical symptoms and family history.
The laboratory will inform the referring clinician as soon as practical if the sample is unsuitable for testing, the identifiers provided are insufficient or the test requested is unclear. It is the responsibility of the laboratory to report the result within the turnaround times indicated. Any factors leading to delay or quality of testing or should be communicated to the referring clinician as soon as practical.
For information on turnaround times, please see our turnaround times page.
Please send samples directly to the laboratory. If necessary most samples can be refrigerated at +4 degree Celsius for a few days without affecting quality. In general samples should not be frozen, however if this is necessary, please discuss this with the laboratory in advance - it will be necessary to send a frozen sample by same day delivery on dry ice.
All clinical specimens, blood and other samples, are potential biohazards and must be packaged to comply with the current regulations on the transport and postage of biological materials. For further details see: biological agents. Samples should be packaged in a way as to maintain patient confidentiality and prevent leakage and/or contamination to couriers and porters.
Where samples are known to pose a specific high risk (eg. HIV, Hepatitis B/C) the nature of the risk must be clearly marked on the referral card. The referral card and specimen container should clearly labelled (for example with danger of infection tape) to indicate its high risk nature. Please contact the laboratory with any queries regarding the appropriateness of sending any potentially high risk samples.
The quality and quantity of extracted DNA will be affected if samples are collected in the wrong containers, stored at extreme temperatures or delayed in transit. This may result in the failure of the test.
The interpretation of results depends on the diagnosis of affected individuals, identification of samples and biological relationships of the individuals being correct.
For advice on referral to Clinical Genetics and general advice on patients please contact the Department of Clinical Genetics.
For advice on cytogenetic referrals please contact refer to the Constitutional Cytogenetics pages.