Final answer:
Kaolin is used in coagulation monitoring to activate the intrinsic pathway and facilitate clotting factor activation, particularly in the aPTT test, which measures the blood's ability to clot and is used for heparin monitoring and diagnosing bleeding disorders.
Step-by-step explanation:
The purpose of using kaolin in coagulation monitoring is to activate the intrinsic pathway of the coagulation cascade. Kaolin acts as a surface that facilitates the activation of clotting factors, particularly factor XII. This action subsequently leads to the conversion of prothrombin to thrombin, which is essential in the formation of fibrin clots. One of the common tests that utilize kaolin is the activated Partial Thromboplastin Time (aPTT) test, which measures the efficiency of the intrinsic and common coagulation pathways. Kaolin is mixed with a blood sample, and the time taken for the sample to clot is recorded. The aPTT test helps in assessing the blood's ability to clot and is often used to monitor patients on heparin therapy or to diagnose bleeding disorders.