Mixing screen (Coagulation)

Test Code

MIXING SCREEN(LOW ISI)WX

Alias/See Also

Hematology

Includes

PT
INR
PTT
PT with mix
PTT with mix
Comment

Preferred Specimen

3 Light blue top tubes

Instructions

Thrombin time recommended for all elevated mixing screens

Transport Temperature

Room temperature

Specimen Stability

Whole blood, unopened tube, centrifuged or uncentrifuged
Non-heparinized patients
Room temperature: 4 hours
Patients for VWF or VIII analysis
Room temperature: 4 hours.
Patients on unfractionated heparin
Centrifuge within 1hr of collection
Room temperature: 4 hours

Plasma aliquot
Room temperature: 4 hours
If not performed same day as draw, freeze platelet-poor aliquot at -60°C.

Setup Schedule

Daily
Mixing Screen may be processed on weekends/off-shifts for emergent situations (immediate mix only – no incubation). Call the West Roxbury hematology lab at 857-203-5328 if emergent mixing screen is needed.

Report Available

TAT 1 day

Limitations

For any elevated mixing study results, the presence of anticoagulant inhibitor drugs such as heparin or direct thrombin inhibitors cannot be excluded.

Reference Range

Test	Reference range	Interpretation
PT	9.8 - 13.3 sec
INR	≤1.1
PTT	27.9 - 37.0 sec
PT with mix
Ptt with mix

Comments

For normal patient who are not on anticoagulation, the INR of 1.1 or lower is considered normal.
Therapeutic range for patients on anticoagulant should be between 2.0-3.5

Performing Laboratory
Test performed in West Roxbury Hematology Lab
Contact West Roxbury: Nolan Raymond 857-203-5980

Last Updated: January 23, 2024

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.