Constitutional - DNA

Postnatal samples for DNA tests

Blood

• Sample type: unclotted blood, with EDTA as anticoagulant
• Quantity: 1 tube with > = 5 ml (for newborns 1 ml is acceptable), sometimes 2 tubes with > = 5 ml
• Instructions for the sampling: instructions for the sampling of blood and bone marrow for DNA tests
• Storage: at room temperature, away from direct sunlight
• Delivery to the lab: within 72 hours after the sample was taken, to deliver before 5 pm (on Fridays before
  2 pm)

Fresh blood (indicated as ‘f-E’ on the application form)

• Sample type: unclotted blood, with EDTA as anticoagulant
• Quantity: >= 5 ml (for newborns 1 ml is acceptable)
• Instructions for the sampling
• Storage: at room temperature (not in the fridge, do not freeze)
• Delivery to the lab: within 48 hours after the sample was taken, to deliver before 5 pm (on Fridays before
  2 pm)
• Remarks:
  • fresh blood is needed for RNA-based tests; for DNA-based tests the blood conditions are less strict (see above: conditions for ‘blood’)
  • in case the CMGG receives the blood later than 48 hours after the sample was taken, it is no longer appropriate for RNA insulation and analysis cannot be carried out.

Cheek brush

• Sample type: cheek brushes or swab
• Quantity: always take two samples
• Instructions for the sampling
• Storage: at room temperature or in the fridge, NOT in a plastic bag!
• Delivery to the lab: within 72 hours after the sample was taken, to deliver before 5 pm (on Fridays before
  2 pm)
• Remarks:
  • Cheek brushes are accepted for a limited number of genetic tests
  • An application form signed or stamped by a doctor is absolutely required, even when the patient takes the sample at home in absence of a doctor

Fresh human tissue other than blood

• Sample type: sterilely taken biopsy (e.g. skin), autopsy sample, tumour tissue or other human tissue
• Quantity: always take two samples
• Processing: put the sample immediately in a sterile container with sterile culture medium or – if not available – sterile isotonic solution (no formalin!)
• Storage: in the fridge (2 - 8° C); transport at room temperature
• Delivery to the lab: within 24 hours after the sample was taken, to deliver before 5 pm (on Fridays before
  2 pm)
• Remarks:
  • Notify the lab by calling the CMGG secretariat: +32 9 332 2477

Formalin-fixed paraffin-embedded tissue

• Sample type: formalin-fixed paraffin-embedded (FFPE) tissue
• Quantity: one block of paraffin
• Storage: at room temperature
• Delivery to the lab: no special precautions required, can be sent by ordinary mail or be delivered before
  5 pm

For DNA tests (f.e. the detection of somatic mutation in tumour tissue) it is crucial that the tissue has been fixed with fresh buffered formalin (10% formalin of neutral pH; formalin of too low pH can cause shearing of the DNA strands) and that a fixation duration of 6 to 72 hours is respected. The time between the ressection of the tissue and the fixation must be as short as possible. Reference: Asco guidelines: Wolff et al. J. Clin. Oncol. 2013, 31: 3997-4013.

DNA

Preferably, we get an EDTA blood sample. If you have the patient’s DNA, the following conditions are appropriate for almost any molecular-genetic test:

• Sample type: genomic DNA isolated from biological tissue
• Quantity: 50-100 µg DNA; OD260/280: 1,80
• Storage: preferably in the fridge (2 - 8° C) or freezer (- 20° C), transport at room temperature
• Delivery to the lab: no special precautions required, can be sent by ordinary mail or be delivered before
  5 pm
• Remarks:
  • mention the purification method and concentration

BIOCHEMICAL TESTS AND NULL-ALLELE TESTING

Fibroblasts

• Sample type: cultured confluent fibroblasts
• Quantity: 2 culture flasks T25 or T80
• Storage: at room temperature; fully filled bottle to avoid cell desiccation
• Delivery to the lab: within 72 hours after the sample was taken, to deliver before 5 pm (Transport at room temperature)
• Remarks:
  • Notify the lab by calling the CMGG secretariat: +32 9 332 2477
  • Please report if streptomycin or penicillin has been added!

Skin biopsy

• Sample type: sterilely taken skin swab
• Processing: put the sample immediately in a sterile container with sterile culture medium or (if not available) sterile isotonic solution (no formalin!)
• Storage: in the fridge (2 - 8° C)
• Delivery to the lab: within 72 hours after the sample was taken, to deliver before 5 pm (Transport at room temperature)
• Remarks:
  • Notify the lab by calling the CMGG secretariat: +32 9 332 2477