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Blood Sciences Test


3x Coagulation tubes

Blood should be collected by clean venepuncture, using 19-21 gauge needles, into a 3ml citrate tube. Minimal stasis should be applied, with free flowing blood. Butterfly type needles may be convenient where multiple sample types are being collected. If blood must be collected through an indwelling cannula, this should be flushed with saline or balanced salt solution and the first 5-10ml blood discarded (try to avoid lines that have contained heparin).

Special Instructions

Only available after prior discussion with a Consultant Haematologist.

If sanctioned, samples will be sent by same day courier to the referral centre.

Factors affecting results

Specimen tubes must be filled correctly.

Test Usage

Aid diagnosis of Thrombotic Thrombocytopenic Purpura


During core working hours:

Haemostasis Laboratory, Bristol Royal Infirmary

Contact: Amanda Clarke or Andrew Mumford (via switchboard)

Weekends & Bank Holidays:

National HUS Centre, Newcastle-Upon-Tyne

Other information: A TTP register now exists. All relevant information is held in electronic format (QP)by the Haematology Lab

Turnaround time

Urgent – Within 12 hours of receipt in the laboratory

Non-Urgent – Within 3-4 days

Clinical Advice

Clinical advice is available from the Haematology Medical team (contact RD&E switchboard on 01392 411611)



Specimen Labelling Procedure
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