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Epic Code LAB321 Mixing Studies, PT

Important Note

There is currently a nationwide shortage of this tube. Please take steps to ensure specimen integrity to reduce recollection. Specimen Tube Shortage (link)

Test Name Alias

Mixing Studies PT | 4118

Interface Order Alias


Quick Collect


Clinical Information

Used to investigate a prolonged prothrombin time, factor deficiency or factor inhibitor.

Collection Instructions

Specimen Collection: Blood


Container(s): 3.2% Na Citrate Tube (blue top)

Preferred Volume to Collect: 8.1 mL (3 full 2.7 mL tube)

Minimum Volume to Collect: 5.4 mL (3 full 1.8 mL tube)

Capillary collect ok: No

Microtainer acceptable: No


Collection Instructions:

Processing Instructions (Laboratory, Outpatient or Off-site collection)

Processed Specimen: Platelet Poor Plasma


Centrifuge/Spin: Yes

Aliquot: Yes


Processing Instructions:

  • Detailed instructions (link): Preparing Platelet Poor Plasma
  • Separate plasma into 4 - 6 aliquots, minimum of 0.5 mL each.
  • Freeze aliquots in plastic transport tubes immediately.

Transport Temperature:

  • Ambient (up to 1 hour in whole blood state)
  • Frozen (plasma only >1 hour)

Rejection Criteria

  • Hemolysis
  • Specimen has been thawed

Specimen Stability

Ambient: Up to 1 hour in whole blood state

Frozen: platelet poor plasma aliquoted and frozen within 1 hour of collection (2 months)

Laboratory Retention: 2 months

Reflex Information

Link: Mandatory reflex approved by MEC

Test Frequency

Available Monday-Thursday, usual TAT 1-4 days.

Reference Range

9.5 - 12.0 seconds

Pathologist interpretation reported with results if indicated.

Performing Department


Performing Department Laboratory Location

Corewell Health Reference Laboratory, Grand Rapids, MI


Prothrombin based clot assay



CDM Code


Epic Test ID


Mayo Access Code


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