Test Catageory
فئة التحليل
Hematology
Refrence Books
كتب مراجع
1. Daice & Lewis Practical Hematology
Skills Required
المهارات المطلوبة
1. Pipetting
2. Timing
Video Resources
مصادر فيديو
غير متوفرة
Purpose of the Test
To assess the intrinsic and common coagulation pathways by measuring clotting time in the presence of a platelet substitute and activating reagent.
Principle
Contact activation of the intrinsic pathway leads to conversion of fibrinogen to fibrin and clot formation. The time taken is proportional to the activity of the intrinsic system.
Equipments
1. Coagulation analyzer
2. Test tubes
3. Pipettes
4. APTT reagent (Contains phospholipid activator and platelet substitute)
5. APTT control plasma
Sample Type
Plasma in 3.2% sodium citrate in a 9:1 ratio
To Prepare the Sample Centrifuge at 1500 x g for 15 minutes.
Procedure
1. Transfer platelet poor plasma to labeled test tubes and incubate at 37°C for 2-3 minutes.
2. Take 100 μL of plasma in the cuvetter and put in the analyzer
3. Then add 100 μL APTT reagent to test tube and incubate for 2 mins.
4. Then add 100 μL Calcium Chloride reagent to test tube and Simultaneouslt start the cloting timer
4. Stop the timer at first sign of fibrin clot formation. Record result in seconds.
| Test | |
|---|---|
| PTT Reagent | 100 μl |
| Plasma | 100 μl |
| Incubation | 2 mins |
| Calcium Reagent | 100 μl |
تختلف خطوات عمل التحليل حسب شركة المحلول المستخدم
Procedure
6. Report the result in Seconds and then calculate the INR
APTT Ratio = Patient APTT / Mean Normal APTT
Reference range: 25-35 seconds
Normal Range
Quality Control:
1. Run two levels of control with each batch of samples.
2. Results should fall within established confidence limits.
3. it is better to repeat the test at least 3 times and then determine the final result
Warning :
1. Improper blood collection can affect results.
2. Anticoagulant therapy prolongs APTT.
M. Sulieman
mohammad@mlsgaate.com
Perform 2 levels of quality control before running patient samples.
QC results should fall within acceptable established range.
