Test Code APC RESIST Activated Protein Resistance (APTT), Plasma
Additional Codes
Sunrise Clinical Manager (SCM) Orderable: Activated Protein C Resistance Assay
AllScripts (AEHR) Orderable: Activated Protein C Resistance Assay
Performing Laboratory
Northwell Health Laboratories
Methodology
Clottable APTT-Based
Reference Values
≥ 2.20 Ratio
Test Classification and CPT Coding
85307
Specimen Required
Container/Tube: Light blue-top (3.2% sodium citrate) tube and a lavender-top (EDTA) tube
Specimen: Full tubes
Transport Temperature: Lavender top tube- Room Temperature and follow collection instructions for light blue top tube.
Collection Instructions:
Note:
- If the light blue top tube is the only tube to be drawn and will be collected using a butterfly set, a “discard” tube (either a plain[non-additive] or light blue) must be partially drawn just to completely fill the collection tubing with blood before collecting the light blue top for testing. Failure to perform this step will result in an under-filled tube that the laboratory will reject.
- Allow blood to fill the tube completely to the line on the tube. The ratio of blood to anticoagulant is critical in coagulation testing and at least a 90% fill is required.
- Immediately mix the specimen by gently inverting the tube 4-6 times to completely mix with the anticoagulant. Failure to perform this can result in a clotted sample, which is unacceptable for testing1. If there is a delay in transport, spin down, spin plasma again, and send citrate platelet-poor plasma and whole blood. Freeze if there is a delay in transport Double-centrifuged specimens are critical for accurate results as platelet contamination may cause spurious results.
- Consent form required for molecular genetic testing (Factor V Leiden).
- Abnormal ratios will reflex to the performance of Factor V Leiden.
Day(s) and Time(s) Performed
1 - 2 times per week
Computer Interface Code
PDM # 5600054