PARTIAL THROMBOPLASTIN TIME, MIXING STUDY

Synonyms: PTT Mixing Study
Computer Code: MPTT
Specimen Collection: Three 2.7 mL (blue top tubes) 90% full. Transport to lab within 3 hours.
Minimum Volume: two 2.7 mL (blue top tubes) 90% full. Transport to lab within 3 hours.
Handling Instructions for Offsite Areas: Maintain at room temperature. If specimen cannot be transported within 2 hours, centrifuge at 3,000 rpm for 20 minutes. Using a plastic pipette, transfer plasma to plastic tube and freeze plasma.
Reference Values: Test to differentiate whether an abnormal PTT is due to a factor deficiency or an inhibitor.
Lab Code: HEM
Requisition: C/H
Test Frequency: Daily
Routine TAT: 4 hrs
Stat TAT: contact lab
CPT Code(s): 856730x2, 85732
LCD or NCD:
Methodology Used:
See Addendum XVII