What is being tested?
Fibrinogen is a coagulation factor, a protein that is essential for blood clot formation. It is produced by the liver and released into the circulation as needed along with over 20 other clotting factors. Normally, when a body tissue or blood vessel wall is injured a process called the coagulation cascade activates these factors. As the cascade nears completion, soluble fibrinogen (fibrinogen dissolved in fluid) is changed into insoluble fibrin threads. These threads cross-link to form a fibrin net and then stabilize at the injury site. The net adheres there, along with aggregated cell fragments called platelets, to form a stable blood clot. This barrier prevents additional blood loss and remains in place until the area has healed.

How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm. As an alternative, particularly in paediatric care, the blood sample is drawn by quickly pricking the fingertip with a lancet.