AnMed Laboratory Services


Partial Thromboplastin Time, Activated  (PTT)

Synonyms:  aPTT, PTT
Specimen:  Blood, (1) Blue (3.2% sodium citrate) top vacutainer tube.
                        Volume:  Full primary tube
Minimum Volume:  Full primary tube
Collection:  Specimen can be uncentrifuged or centrifuged with plasma remaining in the capped tube at room temperature 18-24°C and tested within 4 hours of collection. If testing is delayed and tube may be agitated by travel, separate plasma from the cells within one hour of collection and freeze at -20°C for up to two weeks; -70°C for up to 12 months.
Rejection Criteria:  Clotted; hemolyzed; short filled tube; improper labeling; incorrect specimen type and storage.
Reference Range:  22.4-35.6 seconds
Test Use:  Screening procedure for deficiencies in coagulation factors of the intrinsic coagulation pathway and monitoring heparin therapy. It will detect deficiencies of factors I, II, V, VIII, IX, X, XI, XII, HMWK, and prekallikrein.
Additional Information:  Heparin Nomogram is usually followed for patients on Heparin Protocol at AnMed Health.
Testing Includes: 
Testing Facility:  AnMed Laboratory