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Hemostasis Specimen Management

I am trying to find a chart or article that tells how long plasma is good for hemostasis testing. The question has arisen about fresh samples and frozen samples. We often get requests for add-on tests and need to know how long is too long. Do you know of a resource that will provide this information? Thanks, Deborah Whetzel MT(ASCP), CLS Supervisor, Children’s Hospital of the King’s Daughters.

Hi, Deborah. I suggest you obtain a copy of Collection, transport, and processing of blood specimens for testing plasma-based coagulation assays, approved guideline, 4th ed. Document H21-A5. Wayne, PA: Clinical Laboratory and Standards Institute, 2008. An H21 sample is posted below. The guideline committee is chaired by Dr. Dorothy Adcock-Funk, and here is a brief summary of their recommendations:

  • Coagulation testing specimens should be maintained at room temperature, not refrigerated or iced.
  • Specimens for prothrombin time may be held stoppered and uncentrifuged for up to 24 hours after collection.
  • Specimens for partial thromboplastin time may be held stoppered and uncentrifuged for up to 4 hours after collection.
  • Specimens collected for heparin assay must be centrifuged and the plasma separated within 1 hour of collection.
  • When testing cannot be completed within these time parameters, specimens are centrifuged to produce platelet poor plasma and the plasma is immediately frozen and stored at -70°C.
  • Specimens collected for platelet aggregometry must be tested within 3 hours of collection, and cannot be frozen.
  • Specimens for molecular testing are collected using EDTA and may be refrigerated and stored for up to 72 hours.

You may also find a catalogue of charts, booklets, and pocket guides from BD Vacutainer, Inc. I hope this helps. Geo.
H21-A5 Sample

Comments (2)
Specimen Management
Jul 9, 2013 9:19am

Generally it is recommended to keep samples no more than 2 w
Generally it is recommended to keep samples no more than 2 weeks at -20 C, but recently it has been shown that coagulation factors might be stable (variation less 10%) if stored up to 3 months at average -24 C: Woodhams B. et al Stability of coagulation proteins in frozen plasma. Blood Coagul Fibrinolysis 2001;12:229-36.

Jul 8, 2013 12:26pm

What about freezing samples at -20 C?
What about freezing samples at -20 C?

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