Certified INR value ranges (manual PT technique)
| Lyophilised plasma type | RBT/90 | rTF/95 |
|---|---|---|
| INR, international normalised ratio; PT, prothrombin time; RBT/90, rabbit plain international reference preparation; rTF/95, human recombinant international reference preparation. | ||
| Artificially depleted | 1.6 to 6.3 | 1.6 to 3.4 |
| Individual coumarin | 1.5 to 6.6 | 1.7 to 4.5 |
| Pooled coumarin | 1.7 to 3.9 | 1.8 to 3.4 |