Mixing Study [8922X]

Test Code

CPT Codes
85610, 85730


Prothrombin Time (PT), Activated Partial Thromboplastin Time (PTT)

If the PT is prolonged (>13.5 seconds), the PT-Mix will be performed at an additional charge (CPT code(s): 85611).
If the PTT-LA is prolonged (>40 seconds), the PTT-LA Mix will be performed at an additional charge (CPT code(s): 85732).
If the PTT-LA mix corrects, an incubated PTT-LA Mix is performed at an additional charge (CPT code(s): 85732).

Preferred Specimen
3 mL frozen plasma collected in a 3.2% sodium citrate (light blue-top) tube

Minimum Volume
2 mL

Please submit a separate, frozen vial for each special coagulation assay ordered.

Collect 3 mL plasma in a 3.2% sodium citrate (light blue-top tube), freeze, and ship frozen. The minimum volume of 2 mL citrated plasma is not a sufficient quantity for repeat testing.

General Drawing Instructions: Refer to Quest Diagnostics Nichols Institute Directory of Services under Specimen Collection section, Coagulation Testing, for further information on specimen processing.

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen (-20°C): 7 days
Frozen (-70°C): 90 days

Clot Detection

Setup Schedule
Set up: Mon-Fri evenings; Report available: Next day

Reference Range
See Laboratory Report

Clinical Significance
This is a screening test to aid in distinguishing between factor deficiency or presence of a coagulation inhibitor.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

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.