At a glance
| Analyte | Activated partial thromboplastin time |
|---|---|
| Also called | PTT, APTT, Partial thromboplastin time |
| Method | Clotting, activator and phospholipid |
| Sample type | Citrated plasma |
| Panel | Coagulation |
| Discipline | Coagulation |
| Brand | Mindray |
What aPTT Reagent measures
The activated partial thromboplastin time measures clotting through a different entry point in the cascade from the prothrombin time, and that is exactly why the two are reported together: comparing which of them is prolonged localises where the abnormality lies, whereas either alone shows only that something is wrong. It is used to monitor patients on unfractionated heparin, in pre-operative screening alongside PT, and in the investigation of a bleeding tendency or an unexplained prolonged result. Unlike the prothrombin time it has no standardised ratio equivalent to the INR, so results are compared against the reporting laboratory’s own reference interval and are not directly transferable between laboratories.
How Philippine laboratories run it
Ordered with PT as a pair in pre-operative screening, which is where most Philippine hospital volume comes from, and the two reagents should be scheduled together and in step for that reason. Heparin monitoring adds an inpatient and intensive care stream that is urgent and arrives at any hour. Almost every request form in the country writes this as PTT rather than aPTT, and laboratories reporting it should recognise both names on requisitions, because a form written PTT is asking for this test.
Analyzers it runs on
Calibrator, controls and companion tests
Delivered with both control levels and the rest of the coagulation panel, on the same schedule as aPTT Reagent.
Storage and handling
Refrigerated, with reconstitution and on-instrument stability exactly as the insert directs.
Buying aPTT Reagent in the Philippines
aPTT Reagent is supplied for the C2000-2 / C2000-4 and C3100. We deliver it with Coagulation Control, normal and Coagulation Control, abnormal, because a run held up waiting on a separate order costs the same shift a stock-out does. Delivery is scheduled against your monthly aPTT Reagent count, so the bench is not rationing tests in the last week of the month. How we plan coagulation supply.
Questions about aPTT Reagent
Is PTT the same as aPTT?
In current practice, yes. The activated partial thromboplastin time replaced the older unactivated version, and although most Philippine request forms and clinicians still say PTT, the test being performed is the aPTT. Laboratories should treat a request written PTT as a request for this assay.
Why is there no INR equivalent for aPTT?
No standardised ratio exists for it, so results are not directly transferable between laboratories the way an INR is. Each laboratory reports against its own reference interval, established with its own reagent and instrument. That is worth knowing when a patient brings a result from elsewhere, because the two numbers are not strictly comparable.
Order aPTT Reagent
Tell us your monthly aPTT Reagent volume and we will quote a supply schedule for C2000-2 / C2000-4. We reply within one business day.
Request a quotation