To prevent spurious results due to transfer of anticoagulant between tubes, tubes containing no additive should be filled before those containing anticoagulant.
All specimens, but especially for haematological investigations should be obtained from a free flowing venepuncture. It is important that all specimen collection tubes are filled exactly to the level marked on the tube and mixed gently by inversion. Please ensure that specimen tubes required for haemostatic investigations are collected first.
Details of the correct specimen collection tube for investigations are provided in the
Order of Draw for Multiple Sampling
Please see the order of draw guide: