Department

Haematology

Preferred Sample Type

INR (PT) and Partial Thromboplastin Time (PTT)

2.7mL

Specimen Transport

Standard transport to laboratory

Sample Processing in Laboratory

Sample should be centrifuged

Sample Preparation

Samples for any coagulation tests must be filled to within a tolerance of 10% of the fill line indicated on the sample tube. Any sample filled above or below this level will be reported as overfilled or insufficient and a repeat sample will be required

Turnaround Time

4 hours

Sample Stability

4°C for 12 hours

INR (PT) and Partial Thromboplastin Time (PTT)

Notes

Add on coagulation requests must be made to the laboratory within 12 hours of venepuncture

For the effects of direct oral anticoagulants on coagulation tests click here

Reference Range

INR 0.8-1.2

PT 10 -14 seconds

PTT Ratio 0.8-1.2

PTT 23 - 34 seconds

Paediatric reference ranges can be found here

Specifications

EQA Scheme?: Yes
EQA Status: NEQAS