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Laboratory Medicine

Test catalogue

ADAMTS-13 Activity

Test Name

ADAMTS-13 Activity

Blue top Specimen Type / Requirements

Container Type = Blue (Sodium Citrate)

Minimum Volume = Full draw

9:1 Ratio (9 parts blood to 1 part anticoagulant)

Specimen Handling

Collection Instructions: Must indicate anticoagulant status to avoid delay. A Hematology consult is REQUIRED for inpatient samples (except for patients in 2 Donnelly). Referred-in patients and outpatients can be tested without a Hematology consult.

Referred-in samples must be accompanied by an ADAMTS-13 Request Form filled out by the requesting site. For in- and out-patients only, if the ADAMTS-13 activity is < 0.10 U/mL, the ADAMTS-13 inhibitor test will be reflexed.

Write your initials, date and time of collection on the collection label.

Transportation: In/Outpatients: Send whole citrated blood at room temperature as soon as possible. Referred-in: Send frozen citrated plasma on dry ice. All samples must be sent to the Core Laboratory.

Stability: Specimens are stable for 4 hours post collection at room temperature. Specimens which are not tested within 4 hours can be double-spun to remove the citrated plasma. The citrated plasma is stable at -20°C for up to two weeks or -70°C for up to six months.

Sample Rejection Criteria: Clotted sample, grossly hemolyzed samples, unlabeled or samples with insufficient quantity will be rejected.

Required Documentation

Turnaround Time (TAT)

Routine: 14 days

STAT: 24 - 48 hours

Test Utilization

Reference Value

Very Low: < 0.10 U/mL

Decreased: 0.10 – 0.40 U/mL

Normal: >0.40 U/mL

Test Code




Testing Location

SMH-Special Coagulation

Other Information

Last Updated: June 06, 2019