Laboratory Services

Protime, INR and Activated Partial Thrombin Time

Print this page

Updated Test Information:

Test Description
Protime, INR and Activated Partial Thrombin Time
Synonym(s)

PT, INR, PTT, APTT

Test ID
PTPTT
Specimen Type

Plasma

Specimen Requirements

Light Blue
Aliquot Tube

Specimen Collection / Processing Instructions

Light Blue - Centrifuge immediately, transfer plasma to aliquot tube and freeze at less than -20°C.

Minimum Sample Volume

The sodium citrate collection tube must be filled to 90% of capacity.

Pediatric Min. Volume (if applicable)

The sodium citrate collection tube must be filled to 90% of capacity.

Additional Processing Details

Centrifuge immediately for 15 minutes at 2000-2500 g. Transfer the plasma to an aliquot tube and store frozen at ≤ -20°C. DO NOT store plasma at 2° - 8°C


 CP Accessioning instructions when receiving a sample at room temperature:


Centrifuge, in the small centrifuge, at 4500 for 15 mins – aliquot the plasma into a plastic tube, then centrifuge the aliquoted Plasma at 4500 for 15 mins.  Aliquot this plasma into a plastic tube leaving any remaining cells in the bottom of the aliquot (try not to disturb the bottom 0.2 mL of this 2nd centrifuged tube and you should be good). If a tech can run immediately, you do not need to freeze, otherwise freeze.

Stability

Plasma Na Citrate
  - Frozen (preferred): 14 days
  - Room Temperature: 4 hours
  - Refrigerated: Unacceptable


Unspun Whole Blood in Na Citrate
  -Room temperature: 4 hours
  -Refrigerated: Unacceptable
  -Frozen: Unacceptable

Unacceptable Specimen Conditions

Refrigerated specimen; Quantity not sufficent; improperly labeled specimens; specimens not collected in 3.2% buffered sodium citrate tube; clotted specimens; under or over filled specimen tubes; severe hemolysis; improperly labeled specimens

Methodology

Automated

Estimated TAT

0-2 days

Testing Schedule

Monday-Saturday, & STAT

CPT Code(s)

85730
85610

Reference Range

PT 11.4 – 14.0 seconds
PTT 26 – 40 seconds

Reflex Conditions

None

Performing Lab

Incyte Diagnostics

LOINC Code(s)

5902-2, 6301-6, 14979-9