Test Code PTT Activated Partial Thromboplastin Time (APTT), Plasma
Methodology
TurbidometricPerforming Laboratory
Aspen Valley HospitalSpecimen Requirements
Container/Tube: Light blue-top (sodium citrate) tube(s)Specimen: 1 mL of sodium citrate plasma
Collection Instructions: If there is a delay in transport of >4 hours, spin down and send 1 mL of platelet-poor plasma frozen in plastic vial.
Specimen Transport Temperature
AmbientReference Values
Patients not taking anticoagulants: 24.5-36.0 secondsCritical value (automatic call-back): >90 seconds (unless patient is known to be on heparin)