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22290 Coagulation Consult, Prolonged Clotting Time

Coagulation Consult, Prolonged Clotting Time
Test Code: MIX
Synonyms/Keywords
​Mixing Study, Circulating Inhibitor, Factor Identification
Test Components
​Prothrombin Time, Activated Partial Thromboplastin Time, PT and APTT Mixing Studies
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ 6.75 mL divided into two 1.5 mL aliquots and five 0.75 mL aliquots​ 4.5 mL divided into two 1.5 mL aliquots and two 0.75 mL aliquots​ 3.0 mL divided into one 1.5 mL aliquot and two 0.75 mL aliquots​
Collection Processing Instructions
​Collect in approximately 4-5 Citrated Blue Top Tubes (BTT).  The minimum 3.0 mL citrated platelet poor plasma volume can usually be obtained by drawing two 4.5 mL OR three 2.7 mL blue top tubes.  If more than one coagulation test is ordered, a separate aliquot is needed for each test.
- Collect in Citrated Blue Top Tube (BTT)
- Citrate anticoagulant must be adjusted for HCT >55%.
- Tube must be at least 90% full.
- Invert completely 3-4 times (without shaking) to mix.
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
Platelet Poor ​Plasma Frozen (-70C) ​6 Months
​Platelet Poor Plasma​Ambient​3 Hours
Rejection Criteria
Clotted
Known IV fluid or Hickman line fluid contamination
​Specimens that thaw during storage or transport
​Specimen Tubes under-filled (below the fill line) and over-filled (above the fill line)

​Reject at gross hemolysis

​Frozen whole blood
​Specimens with abnormal results that have a HCT >55% that have not had the citrate anticoagulant adjusted
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield ​Monday through Friday ​6-8 hours PT/APTT substitutions/Optical clot detection/Sysmex CS-2500
Test Information
​Reflex testing for PT and APTT substitutions, factor assays and/or circulating inhibitor assays (DRVVT and SCT) will be performed based on the results of the PT (INR), APTT, mixing studies and the basic coagulation scheme.
Reference Range Information
Performing Location Reference Range
​Marshfield See individual test listings for reference ranges.​
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
85730​ APTT​
85732​ Prothrombin Time
85610​ ​2 APTT Substitution ​If needed
85611​ PT substitution​ If needed
85613​ DRVVT​ If needed
85732​ SCT If needed
Varies​ Factor assays vary with follow-up​ If needed
Synonyms/Keywords
​Mixing Study, Circulating Inhibitor, Factor Identification
Test Components
​Prothrombin Time, Activated Partial Thromboplastin Time, PT and APTT Mixing Studies
Ordering Applications
Ordering Application Description
​Centricity ​Mixing Study-PT/APTT
​Cerner ​Mixing Study (Factor Identification)
​COM ​Mixing Study (Factor ID)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ 6.75 mL divided into two 1.5 mL aliquots and five 0.75 mL aliquots​ 4.5 mL divided into two 1.5 mL aliquots and two 0.75 mL aliquots​ 3.0 mL divided into one 1.5 mL aliquot and two 0.75 mL aliquots​
Collection Processing
​Collect in approximately 4-5 Citrated Blue Top Tubes (BTT).  The minimum 3.0 mL citrated platelet poor plasma volume can usually be obtained by drawing two 4.5 mL OR three 2.7 mL blue top tubes.  If more than one coagulation test is ordered, a separate aliquot is needed for each test.
- Collect in Citrated Blue Top Tube (BTT)
- Citrate anticoagulant must be adjusted for HCT >55%.
- Tube must be at least 90% full.
- Invert completely 3-4 times (without shaking) to mix.
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
Platelet Poor ​Plasma Frozen (-70C) ​6 Months
​Platelet Poor Plasma​Ambient​3 Hours
Rejection Criteria
Clotted
Known IV fluid or Hickman line fluid contamination
​Specimens that thaw during storage or transport
​Specimen Tubes under-filled (below the fill line) and over-filled (above the fill line)

​Reject at gross hemolysis

​Frozen whole blood
​Specimens with abnormal results that have a HCT >55% that have not had the citrate anticoagulant adjusted
Test Components
​Prothrombin Time, Activated Partial Thromboplastin Time, PT and APTT Mixing Studies
Reference Range Information
Performing Location Reference Range
​Marshfield See individual test listings for reference ranges.​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield ​Monday through Friday ​6-8 hours PT/APTT substitutions/Optical clot detection/Sysmex CS-2500
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
85730​ APTT​
85732​ Prothrombin Time
85610​ ​2 APTT Substitution ​If needed
85611​ PT substitution​ If needed
85613​ DRVVT​ If needed
85732​ SCT If needed
Varies​ Factor assays vary with follow-up​ If needed
For most current information refer to the Marshfield Laboratory online reference manual.