APTT 1:1 Mix (incubated)
| Also Known as (Alias) | PTT |
| Indications | Patient with prolonged aPTT and suspected acquired factor inhibitor, particularly acquired FVIII inhibitor |
| Method | Clottable |
| Test Information | Reflexive test if the aPTT 1:1 mix test is abnormal and etiology unknown. |
| Additional Test Information | If a specific inhibitor is suspected, then a 1:1 mix (patient plasma : normal plasma) is incubated at 37°C for 60 minutes. Then an aPTT is repeated. |
| Sample Requirements | Whole Blood: 3.2% Sodium Citrated (blue top) OR Frozen Plasma |
| Requested Volume | Two 5 ml 3.2 sodium citrated (blue top) tubes as whole blood OR Frozen plasma in 4 X 1mL aliquots in plastic tubes |
| Minimum Volume or Pediatric volume | Frozen Plasma: at least 0.5ml in 2 plastic tubes. |
| Sample Information | Whole blood is preferred for testing but if it is not possible to send whole blood tubes TO ARRIVE HERE WITHIN 3 HOURS of collection then send frozen plasma: Centrifuge blue top tubes at 1500g for 15 minutes and remove the plasma and centrifuge a second time at 1500g for an additional 15 minutes. Aliquot approximately 1 ml of plasma into 4 plastic tubes, and freeze. |
| Shipping Information | Whole Blood: Send at ambient temperature (18-25C) and must be received within the lab in less than or equal to 3 hours after collection. Frozen Plasma: send on dry iceSend samples to: Bloodworks Northwest For additional information, please see Ordering Information |
| Requisition Form | RFT- Hemostasis Reference Laboratory |
| Transaction Code | 3200-10 |
| CPT Codes | 85730 |
| Test Schedule | Monday – Friday |
| Turn around Time (analytic time) | 1 Business Day |
| Report/ Results | Fax number required to receive report |