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Regional Medical Lab
Test Directory


Inhibitor Screen

Test Number: 1516550
Revision Date 04/09/2021
Test Name Methodology LOINC Code
PT 1:1 Mixture (Room Temp)
Clot Detection  
PTT 1:1 Mixture (Room Temp)
Clot Detection  
PTT-LA 1:1 Mixture (Room Temp)
Clot Detection 67097-6 
PT 1:1 Mixture (Incubated)
Clot Detection  
PTT 1:1 Mixture (Incubated)
Clot Detection  
PTT-LA 1:1 Mixture (Incubated)
Clot Detection  
Inhibitor Screen Interpretation
Specimen Specimen Volume (min) Specimen Type Specimen Container Transport Environment
Preferred 22 mL (16 mL) Whole Blood Sodium Citrate 3.2% (Blue Top) Room Temperature
Alternate 1 12 mL (9 mL) Double Spun Plasma Sterile, Capped Plastic Tube Frozen
Instructions Please list the patient's anticoagulant on the "Coagulopathy Questionnaire Form" and submit with specimen or fax to 918-744-3236.
Please indicate anticoagulant therapy.
Collect 6-8 Sodium Citrate 3.2% (Blue Top) tubes.
Each 2.7mL Sodium Citrate 3.2% (Blue Top) tube must be filled to the proper level, no hemolysis. Improperly filled tubes can give erroneous results. Whole blood must be transported to lab immediately.
If testing cannot be started within 4 hours of collection the specimen must be double spun then 1.5mL plasma aliquot from each tube into individual plastic aliquot tubes and freeze. 
Do not pool aliquots together!
Testing Schedule Mon - Fri 
Expected TAT Testing dependent  
Clinical Use Specific factor inhibitors are immunoglobulins with specificity for a single coagulation protein. The most common specific inhibitors are antibodies produced in relation to factor VIII. Nonspecific inhibitors, such as lupus anticoagulants, are also detected. 
Notes If PT Mix is performed 85611X2
If PTT Mix is performed 85732X2
If PTT-LA Mix is performed 85732X2

Testing includes a pathology interpretation.
CPT Code(s) See Test Notes
Lab Section Coagulation