Contacts
Advice is available from the laboratory Monday-Friday, 9am-5pm.
Sample transit and delivery address
Samples for Vitamin K, Vitamin K Epoxide, Superwarfarin, Warfarin, Warfarin Enantiomers and PIVKA can be sent by post.
Postal requests for Homocysteine, Methylmalonic acid, Tetrahydrofolate and 5-Methyltetrahydrofolate should be sent on ice.
Current postal regulations can be found in the leaflet "Prohibited and Restricted Goods", Ref. RMN/15/93/B and "Handy guide to inland services", Ref-RMND05/98/A5.
Samples should be sent to:
Dominic Harrington
The Haemostasis and Thrombosis Centre
1st floor, North Wing
St Thomas’ Hospital
Westminster Bridge Road
London SE1 7EH
Laboratory staff contacts
For advice on any of the analytes below, please contact:
Dr Dominic Harrington
Tel: 020 7188 6816
Email: dominic.harrington@gstt.nhs.uk
For Vitamin K1, vitamin K1, 2-3 epoxide, PIVKA II, Warfarin and Superwarfarin: Dr Martin Shearer. Tel: 020 7188 2801. Email: martin.shearer@gstt.nhs.uk
Analytes
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Superwarfarin and warfarin
Specimen collection
Sample required: serum or plasma
Venous blood (4-5 mL) should be collected from a peripheral vein into plain tubes (serum) or tubes containing a suitable anticoagulant such as EDTA or heparin (plasma) and the tubes inverted 8-10 times without shaking to ensure proper anticoagulation. Whole blood collected into sealed vacuum tubes can be stored at 4°C for 24-48 hours.
Separate the serum/plasma from red blood cells by centrifugation (2,300 rpm, 10 min).
Transfer serum/plasma to a labelled glass or plastic tube using a disposable glass pasteur pipette.
Mark request card for the attention of Dominic Harrington.
Warfarin
Theraputic range= 0.7 - 2.3mg/L
Important: Whole blood is not suitable
Results will be made available within 10 days of reception.
Please contact Dominic Harrington regarding superwarfarin data interpretation.
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PIVKA II
Specimen collection
Sample required: serum
Venous blood (1-2 mL) should be collected from a peripheral vein into plain tubes (serum). Separate the serum from red blood cells by centrifugation (2,300 rpm, 10 min).
Transfer serum to a labelled glass or plastic tube using a disposable glass pasteur pipette.
Mark request card for the attention of Martin Shearer.
Reference Range= <0.15AU
Important: Whole blood is not suitable
Results will be made available within 10 days of reception.
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Homocysteine
Specimen collection
Sample required: serum or plasma
To exclude the influence of recent dietary intake it is preferable that blood samples should be collected after an overnight fast. Venous blood (4-5 mL) should be collected from a peripheral vein into a tube containing EDTA and the tube inverted 8-10 times without shaking to ensure proper anticoagulation. Whole blood should be placed on ice immediately.
Separate the plasma from red blood cells by centrifugation (2,300 rpm, 10 min).
Immediately transfer plasma to a labelled glass or plastic tube using a disposable, glass pasteur pipette.
Mark request card for the attention of Dominic Harrington.
Reference Range= <15µmol/L
Important: Whole blood is not suitable
Special notes: Plasma must be removed from red blood cells at the earliest opportunity. Failure to comply will result in overestimation of plasma homocysteine concentration.
Results will be made available within 10 days of reception.
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Methylmalonic acid
Specimen collection
For advice phone laboratory prior to request.
Sample required: 2ml serum or plasma
Venous blood (4-5 mL) should be collected from a peripheral vein into a tube containing EDTA and the tube inverted 8-10 times without shaking to ensure proper anticoagulation. Whole blood should be placed on ice immediately.
Separate the plasma from red blood cells by centrifugation (2,300 rpm, 10 min).
Immediately transfer plasma to a labelled glass or plastic tube using a disposable glass pasteur pipette.
Important: Whole blood is not suitable.
Mark request card for attention of Dominic Harrington
Reference Range. Please contact the laboratory for advice.
Special notes: Plasma must be removed from red blood cells at the earliest opportunity.
Results will be made available within 10 days of reception.
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Vitamin K1, vitamin K1, 2-3 epoxide
Sample required: serum or plasma
To exclude the influence of recent dietary intake it is preferable that blood samples should be collected after an overnight fast. Venous blood (4-5 mL) should be collected from a peripheral vein into plain tubes (serum) or tubes containing a suitable anticoagulant such as EDTA or heparin (plasma) and the tubes inverted 8-10 times without shaking to ensure proper anticoagulation. Whole blood collected into sealed vacuum tubes, protected from light can be stored at 4°C for 24-48 hours without detectable loss of the vitamin.
Separate the serum/plasma from red blood cells by centrifugation (2,300 rpm, 10 min).
Under subdued lighting transfer serum/plasma to a labelled glass tube using a disposable plastic pasteur pipette.
Mark request card for the attention of Dominic Harrington.
Vit K1 Ref Range:
- Fasting: 0.17 - 0.68µg/L (median 0.37µg/L)
- Non Fasting: 0.15 - 1.55µg/L (median 0.53µg/L)
Important: Whole blood is not suitable
Special notes: Protect sample from light
Results will be made available within 10 days of reception.
Please contact Dominic Harrington (+44 (0)20 7188 6816) regarding ref. ranges for Vit K1, 2-3 epoxide.