Blood samples for Molecular Genetics tests
- Blood for molecular genetics DNA should be collected in potassium EDTA (KE) tubes.
- Send to the laboratory as soon as possible.
- Before sending, store in a refrigerator. (DO NOT FREEZE)
- Samples for DNA testing only should be sent directly to Molecular Genetics.
Blood samples for Cytogenetic and Molecular Genetics tests
(including rapid QF-PCR, qPCR and MLPA),
TWO specimen tubes are required; one a Lithium Heparin specimen tube, the other an EDTA (KE) tube.
Minimum blood volumes required in each tube: Adults 3-5ml: Child 3ml: Newborn 1ml
If this is not available, blood specimens should be refrigerated. (DO NOT FREEZE)
DNA samples from other Genetics laboratories
A 2µg DNA sample, ideally at a concentration ≥50µg/ml, is requested for gene sequencing analyses.
Smaller amounts can be accepted for simple PCR based tests, or when only limited amounts are available – please contact lab to discuss.
DNA should be supplied in water or TE buffer (or other buffer compatible with PCR amplification), with actual concentration stated in accompanying document.
Sample labels
- Referring clinicians are requested to comply with NHS Lothian policy on Mandatory Data Set requirements for Patient Identification on laboratory requests.
- Printed labels should be used wherever possible.
- If no printed label is available the following information must be legibly written on the referral form:
- Patient identifier number (CHI or NHS number), Surname, Forename, Date of Birth, Gender. If the CHI/NHS number is not available, the data set must include first line of patient address and postcode. To comply with separate NSD requirements we ask that the patient postcode be included in all cases. Failure to comply with this policy will result in the sample being rejected or the result delayed.
- The sample must be labelled with Surname, Forename (preferably, or initial), Date of Birth, Sample date.
Infecton Control
Genetic service laboratories handle samples in accordance with NHS Lothian specimen policy which is contained in the NHS Lothian Infection Preventation and Control Manual.
(This document is available to NHS Lothian users only on the Infection Control intranet site.)
The Cytogenetics Laboratory cannot accept samples from patients who have, or are suspected of having, Group 3 or 4 pathogens. The DNA laboratory is however able to extract DNA from these samples which must be labelled with a ‘Danger of Infection’ sticker.
Samples from individuals with a confirmed or suspected diagnosis of CJD are not extracted by the Molecular Genetics laboratory. DNA from such samples will be tested after extraction by the CJD Unit. Samples should be sent to Molecular Genetics, labelled with a ‘Danger of Infection’ sticker, with the CJD status clearly indicated on the referral form.
Packaging of samples for transport
It is the responsibility of those taking and dispatching specimens to the laboratory to ensure that these samples are sent in accordance with any national guidelines and/or local policies for the packaging, labelling and transport of biological material.
The HSE documents available at the HSE website defines samples of materials such as blood, tissue, excreta, secreta etc collected from humans to be considered, as a minimum, Category B infectious substances.
U.K. packaging, labelling and transport requirements for samples from otherwise healthy individuals or where there is no reason to suspect that they are suffering from a severe infectious disease are below and are derived from Packing Instruction 650 in European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) (2017)
The ADR instructions state that human specimens for which there is minimal likelihood that pathogens are present are not subject to ADR if the specimen is carried in a packaging which will prevent any leakage and which is marked with the words “Exempt human specimen”.
The packaging is deemed to comply with the above requirements if it meets the following conditions:
- The packaging consists of three components:
- (i) leak-proof primary receptacle(s);
- (ii) a leak-proof secondary packaging; and
- (iii) an outer packaging of adequate strength for its capacity, mass and intended use, and with at least one surface having minimum dimensions of 100 mm × 100 mm;
- For liquids, absorbent material in sufficient quantity to absorb the entire contents is be placed between the primary receptacle(s) and the secondary packaging so that, during carriage, any release or leak of a liquid substance will not reach the outer packaging and will not compromise the integrity of the cushioning material;
- When multiple fragile primary receptacles are placed in a single secondary packaging, they are either individually wrapped or separated to prevent contact between them.
Packages should be clearly labelled with the delivery address and sender details.
Mark with the words “EXEMPT HUMAN SPECIMEN”
Labels must be durable, legible and clearly visible on the outside of the packaging.
