• Heparin infusion with ACT (activated clotting time) test [8]
  • Whole blood test
  • It is performed by adding whole blood to a tube containing a surface activator (such as celite or kaolin)
  • Measures either the mobility of a magnet during clot formation or the change in velocity of movement through blood as it clots 
  • Used to monitor moderate-high doses of unfractionated heparin therapy (UFH).

Figure 3: Activated clotting time test[9]

• aPTT (Activated partial thromboplastin time) test [8]
  • Plasma-based  
  • It is performed by mixing citrated plasma with silica, a synthetic phospholipid, and calcium to initiate clot formation
  • Optical method- clot formation is measured by a change in optical density (% absorbance of light by material) 
  • Mechanical method- clot detection monitors the movement of a steel ball within the test solution

https://www.myupchar.com/en/test/activated-partial-thromboplastin-time-test