Test Overview

Test Methodology

(14)C-Serotonin Release Assay (SRA)

Test Usage

Detection of heparin-dependent platelet antibodies.

Reference Range*

Negative. A positive result requires >20% release of serotonin with low dose heparin and

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

The presence of "non-drug" antibodies reactive with platelets (HLA Class I, autoantibodies, platelet-specific antibodies, etc.) in the patient’s serum can induce heparin independent release of serotonin in the SRA.

Test Details

Days Test Performed

Monday - Saturday

Analytic Time

1 - 3 days

Soft Order Code


MiChart Code

Heparin Induced Serotonin Release Assay



Heparin Antibodies
Heparin Associated Thrombocytopenia and Thrombosis
Heparin Associated Thrombosis (HAT)
Heparin Dependent
Heparin Dependent Antiplatelet Antibodies
Heparin Induced Serotonin Release Assay
Heparin Induced Thrombosis (HIT)
Heparin-Associated Throbocytopenia and Thrombosis
Heparin-Associated Thrombosis (HAT)
Heparin-Dependent Antiplatelet Antibodies
Heparin Serotonin Release Assay
Heparin-Induced Thrombosis (HIT)
Platelet Aggregation Factor
Platelet Aggregation Factor, Heparin Dependent
SRA (Serotonin Release Assay)
Serotonin Release, Heparin-Induced
Serotonin Secretion Assay for HAT
Serotonin Releasing Assay
Heparin-Dependent Platelet Antibody (SRA) - Unfractionated Heparin

+ See More



Laboratory Reference

BloodCenter of Wisconsin 5508

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Specimen Requirements

Offsite Collection Instructions

Collect specimen in a red top tube; do not use SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate. Citrated or ACD plasma is acceptable if serum is not available. Specify Lovenox® (LMWH) or Unfractionated Heparin (UFH).

Rejection Criteria

SST tube not acceptable.


This test is not indicated if the Heparin Antibody Assay (HITAB) is negative.


Red Top Tube

Normal Volume

5 mL serum

Minimum Volume

1 mL serum

Additional Information

Requests for the Serotonin Release Assay will be sent to the MLabs Coagulation Laboratory for confirmation of a positive screen for Heparin Antibody Assay (HITAB) at an additional charge prior to forwarding to BloodCenter of Wisconsin. If the Heparin Antibody Assay is negative the Serotonin Release Assay will be cancelled with a comment added to both test orders indicating the reason for cancellation. Test sent to BloodCenter of Wisconsin.

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