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HelpTest Code LAB325 Activated Partial Thromboplastin Time (APTT)
Department
HEMATOLOGY
Collection Requirements
Do not order for patient on heparin therapy.
Must be a full draw.
Mix thoroughly immediately after collection.
Therapeutic APTT’s can only be drawn at POC and Mackinaw.
Primary Collection Container
Blue 2.7 mL (Citrate)
Transport
Plasma frozen
Preferred Transport Temperature
Frozen
Processing
Mix tube thoroughly before centrifugation.
If freezing, prepare using the following method:
Centrifuge specimen. Use a plastic pipette to transfer top three-quarters of plasma into labeled plastic tube. When removing the plasma layer, be careful not to disturb the cell layers. Plasma separated from cells goes back into the centrifuge for a second spin. After the second spin, use a pipette again to transfer plasma to a new set of labeled aliquot tubes, then freeze.
Stability
Ambient: 4 Hours
Refrigerated: Unacceptable
Frozen: Unacceptable
Processed:
Ambient: 4 hours
Refrigerated: Unacceptable
Frozen: 2 weeks
Minimum Testing Volume
1.0 mL
Reference Range
By report
Methodology
Turbidimetric Clot Detection. ACL Top
Performed
Sunday – Saturday
Reported
Varies
CPT Codes
85730
Unacceptable Conditions
Hemolyzed, clotted, short draw, refrigerated and serum specimens. Frozen whole blood. Non-frozen plasma.
Additional Information
Therapeutic APTTs may never be frozen. TAPTTs drawn at Mackinaw must be run at Mackinaw, and TAPTTs drawn at POB must be run at Core Lab. No other outpatient facilities are permitted to draw TAPTTs.