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Order Code CA004
Turnaround Time 24 hours
Specimen Requirements
Specimen Source
Transport Container
(Specimen Container)

Light Blue (Na-Citrate)

Preferred Specimens
Minimum Volume (uL)
90% fill required
Collection Instructions
(Transport Temperature)
Transport at Room Temperature
Specimen Stability
Temperature Period
Room temperature 48 hours (unspun)
Frozen Unacceptable
Special Instructions

Blood must be filled to the marked line

Test Details
The aPTT reagent consisting of silica mixed with synthetic phospholipid is mixed with the patient plasma. The silica provides a negatively-charged particulate surface for the activation of the contact pathway of coagulation. Calcium chloride is then added to the sample/reagent mixture to initiate clot formation. The time to clot formation is measured photo-optically.
Clinical Significance

The APTT explores the coagulation factors XII, XI, IX, VIII, X, V, II and I except the platelets

Reference Ranges

24.1 – 35.1 seconds