Prothrombin Time with INR Collections

Supply #38445 Light Blue 4.5mL 3.2% SODIUM CITRATE

Test code: 8847

CPT code(s): 85610

Methodology: Photo-optical Clot Detection

Clinical Significance: Screening test for abnormalities of coagulation factors that are involved in the extrinsic pathway. Also used to monitor effects of Warfarin therapy and to study patients with hereditary and acquired clotting disorders.

Test FAQ: Prothrombin Time with INR

Alternative Name(s): PT

Collection Guide: 

Supply: 38445 Light Blue 4.5mL 3.2% SODIUM CITRATE

Preferred Specimen: One Full Unopened 3.2% Sodium Citrate (Light Blue-Top) Tube


A completely filled tube is necessary because the correct ratio of blood to citrate is critical (9:1). Mix by gentle inversion 3-4 times. Do not uncap.

Instructions: a completely filled tube is necessary because the correct ratio of blood to citrate is critical (9:1). Mix by gentle inversion 3-4 times. Do not uncap. Minimum Volume Ratio of blood to citrate is critical. Submit difficult draws in pediatric (light blue-top) tube.

Transport Container: 3.2% Sodium Citrate (Light Blue-Top) Tube

Transport Temperature: Room Temperature

Specimen Stability:
Unopened Light Blue-Top Tube
  • Room Temperature: 48 Hours
Reject Criteria:
  • Improper Blood To Citrate Ratio
  • High Hematocrit
  • Improper Blood Collection

For additional supply or collection device information, please contact DLO's Customer Service at (800) 891-2917, option 2.

The CPT codes provided 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.