Days Set Up
Analytic Time

2 days

Soft Order Code

Test Updated:


Platelet Factor 4 Antigen
PF4 Antigen

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Test Overview

Test Methodology


Test Usage

Beta thromboglobulin, along with platelet factor 4, are considered sensitive markers of platelet activation. These alpha granule proteins are released with in vivo or in vitro platelet activation and are virtually absent from plasma in healthy individuals.

Reference Range

<75 IU/mL

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

Specimen Requirements

Collection Offsite

Tubes containing 0.5 ml of CTAD anticoagulant specially prepared by Esoterix Coagulation are available from MLabs. Collection instructions: Perform the venipuncture using a butterfly needle set and a two-syringe technique. Discard the first syringe after 2 ml of blood have been collected, then collect 5 ml of blood in the second syringe. Gently express 4.5 ml of blood from the syringe gently down the side of the CTAD tube. Cap and invert gently three times and place on ice for at least 15 minutes. Centrifuge tube at 2500 g for 30 minutes in a refrigerated centrifuge within 1 hour of collection. Aliquot one-third of the plasma from the middle region of the plasma portion into a plastic vial and freeze at -70 degrees. Transport frozen on dry ice.

Normal Volume
2 ml CTAD plasma
Minimum Volume
1 ml CTAD plasma

Billing Information

CPT Code
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.