Prothrombin Time (PT)

Method Name

Photo-Optical Clot Detection


Prothrombin Time; Protime; PT; INR, Protime

Specimen Required

One full 2.7 mL (3.2% sodium citrate) blue top tube. Specimen will be rejected if the tube is underfilled or overfilled.

Specimen Minimum Volume

2.7 mL of blood

Specimen Stability Information

Specimen is stable for 24 hours (centrifuged or uncentrifuged; at room temperature)

Performing Laboratory

As ordered. Turn around time is 4 hours.

Reference Values

10.2 – 12.9 seconds