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Test Code
PTTP
Test Name
Activated Partial Thromboplastin Time Mixing Study
CPT Codes
85730
Included Tests
  • Activated Partial Thromboplastin Time

Reflexed when appropriate:

  • Thrombin Time
  • Reptilase Time
  • Activated Partial Thromboplastin Time Mixing Study
  • Activated Partial Thromboplastin Time Mixing Study, Incubated
Expected Turnaround Time
1 - 4 days
Clinical Utility

Distinguish specific (ie, factor VIII) and nonspecific (lupus anticoagulant) inhibitors; determine heparin presence; detect single or multiple factor deficiencies.
Specimen and Container Info

Specimen Type: Plasma  

Collection Container: 2 Full Light Blue Top (Sodium Citrate) 
Collection Instructions

Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio.

Processing and Submission Instructions

Create platelet poor plasma according to the Specimen Collection and Processing Guidelines for Coagulation Testing.

Patient Preparation
Testing is contradictory for patients on anticoagulant therapy.
Transport Instructions
  • Inpatient: Transport to the laboratory at room temperature.
  • Outpatient: Transport to the laboratory frozen. 
Stability Requirements

Room Temperature

4 hours

Frozen

Platelet poor plasma: 14 days
Causes for Rejection
  • Clotted specimen
  • Specimen past stability
  • Specimen not properly filled
  • Specimen thawed in transit
Methodology
Mechanical Clot Detection
Reference Intervals

See Indvidual Test Listings.
Performing Location
Roble Road Core Laboratory
Alternate Names
  • PTT Mixing Study
  • APTT Mixing Study
Testing Schedule
Routine, Monday - Friday no holidays
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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