Blood Cells & Formed Elements of the Blood
Clotting (Coagulation) Time Test
Introduction to The Clotting Time Test:
Although imprecise, the whole-blood clotting time test is one of the simplest methods to determine how well the clotting process is functioning. This test determines how long it takes to initiate the intrinsic coagulation pathway after blood enters a glass tube.
- A finger is lanced an a small drop of blood is allowed to accumulate.
- The time is noted, then blood is drawn up into a nonheparinized glass tube.
Negative charges associated with the glass will initiate the intrinsic coagulation pathway.
- After 2 minutes, a small portion of the glass tube is broken off. Other pieces of the tube are then broken off every 30 seconds.
- If the intrinsic coagulation pathway is functioning normally, strands of fibrin will form and adhere to edges of the broken glass within 2 to 6 minutes.
Clotting Time Quiz