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Test Catalog

Test ID: WRF    
Warfarin, Serum

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Specimen Type Describes the specimen type needed for testing

Serum Red

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Container/Tube: Red top

Specimen Volume: 3 mL

Collection Instructions: Spin down within 2 hours of draw.

Forms: If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen (

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

1.1 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected


Mild OK; Gross OK


Mild reject; Gross reject


Mild OK; Gross OK


Serum gel tube


Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
Serum RedRefrigerated (preferred)21 days
 Ambient 28 days
 Frozen 28 days