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Oxford University Hospitals NHS Foundation Trust

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Molecular Genetics specimen requirements

General Specimen requirements

All samples MUST be accompanied by a referral form

Some samples may require a pre-referral form

Blood samples

EDTA tubes only

  • Adults 5mls, Children 2-5mls, Neonates >1ml, All cystic fibrosis referrals 1ml
  • Blood samples can be transported at room temperature and should arrive within 48 hours of collection.
  • Blood can be stored at 4oC if there is a delay between collection and dispatch. Blood samples must NOT be frozen.

Tissue samples (see below for muscle/liver biopsies for mitochondrial analysis)

  • Collect samples in sterile Universals containing 10ml of tissue transport medium (supplied by the Cytogenetics Laboratory, contact 01865 226001).
  • Larger samples, which will not fit into a 20 ml Universal, should be sent dry in a plastic sterile container.
  • Do NOT fix these tissues.
  • Tissue samples can be transported at room temperature and they should be sent to arrive as soon as possible after collection, i.e. by hospital transport or courier.

Muscle/liver biopsies (for mitochondrial genetic analysis)

  • Snap frozen immediately in liquid nitrogen.
  • Ideally >50mg tissue; if quantity is limited 5-10mg may be sufficient
  • Packaged on dry ice and sent by courier.
  • The laboratory should be warned in advance of their dispatch.
  • Avoid sending samples to arrive at the weekend or just prior to a Bank Holiday.

Saliva samples

  • Samples should be collected in Oragene.DNA collection vials (supplied on request by the DNA Laboratory, contact 01865 226001).
  • Once the saliva sample has been mixed with the Oragene.DNA solution it is stable at room temperature for a few years (refer to the manufacturer's collection protocol supplied with each kit).
  • Collection vials can be returned to the laboratory by 1st class post at room temperature.

Urine samples (for mitochondrial genetic analysis)

  • 20ml of an early morning sample in a suitable sterile container, such as 20ml Universal.
  • Ensure sample will arrive in the laboratory within 24 hours of collection (send by courier if necessary).
  • Avoid sending samples to arrive at the weekend or just prior to a Bank Holiday.

DNA samples

  • DNA samples can be transported at room temperature. DNA is stable for one year at room temperature if suspended in a suitable buffer, e.g. TE.
  • DNA samples should be sent door to door to arrive as soon as possible; i.e. 1st class post is satisfactory for most samples, overnight courier transport is preferable for urgent samples, e.g. for prenatal analysis.
  • If there is an unavoidable delay prior to dispatch, DNA samples can be stored in a refrigerator at 4oC.

Fixed tissues and tissue slides

  • Formalin fixed paraffin embedded (FFPE) tissue in blocks are stable at room temperature and require no special posting.
  • FFPE tissue sections mounted on slides need to be in a slide box and packaged with plenty of padding.

Delays in transit can result in sample failure or sub-optimal results
Blood is stable at room temperature for <7days, DNA yield, but not quality, will decrease over time (Nederhand R.J. et al., 2003 J of Thrombosis and Haemostasis 1: 987-991)

Additional samples types

Additional samples types may be accepted for analysis. Clinicians are advised to contact the laboratory to discuss specific specimen requirements prior to arranging specimen collection.

Last updated: 04 April 2019 by Claire Scott.