Days Set Up
Analytic Time

7 days

Soft Order Code

Test Updated:


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Find a Requisition

All specimens should be accompanied by a requisition.

Submitting Specimens

Learn about how to properly label and where to ship specimens.

Order Kits and Supplies

MLabs provides all the supplies necessary for the collection of specimens.

Test FAQ

Visit our provider FAQ and learn about common questions to ordering tests.

Test Overview

Test Methodology

see individual tests

Test Usage

Study to determine Protein C or Protein S causes of venous thrombosis.

Reference Range

Interpretive report provided for abnormal results

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

Specimen Requirements

Collection Offsite

Collect specimens in 3 blue top (citrate 3.2%) tubes. Mix by inversion. Specimens should arrive at the lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into 3 plastic tubes, and freeze the specimen within 4 hours of collection. Transport frozen specimens on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.

Please provide clinical history (brief description of the reason for testing, e.g., history of easy bruising and menorrhagia, family history of von Willebrand disease) and a listing of current and recent medications, including oral contraceptives, anticoagulants, and factor replacement therapy/DDAVP.

Blue Top Tube
Normal Volume
3 full 2.7mL tubes or 7mL plasma (three 1mL aliquots)
Minimum Volume
3 full 1.8mL tubes or 7mL plasma (three 1mL aliquots)

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.