Euglobulin lysis time
Encyclopedia
The euglobulin lysis time (ELT) is a test that measures overall fibrinolysis
. The test is performed by mixing citrated platelet-poor plasma
with acid in a glass test tube. This acidification causes the precipitation of certain clotting factors in a complex called the euglobulin fraction. The euglobulin fraction contains the important fibrinolytic factors fibrinogen
, PAI-1, tPA
, plasminogen, and to a lesser extent alpha 2-antiplasmin
. The euglobulin fraction also contains factor VIII
.
After precipitation, the euglobulin fraction is resuspended in a borate solution. Clotting is then activated by the addition of calcium chloride at 37 C. Historically, subsequent amount of fibrinolysis was determined by eye, by observing the clot within the test tube at ten minute intervals until complete lysis had occurred. Newer automated methods have also been developed. These methods use the same principle as the older technique, but use a spectrophotometer to track clot lysis as a function of optical density.
Fibrinolysis
Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. This process has two types: primary fibrinolysis and secondary fibrinolysis...
. The test is performed by mixing citrated platelet-poor plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
with acid in a glass test tube. This acidification causes the precipitation of certain clotting factors in a complex called the euglobulin fraction. The euglobulin fraction contains the important fibrinolytic factors fibrinogen
Fibrinogen
Fibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...
, PAI-1, tPA
TPA
TPA may refer to:* Third-Party Audit, an Audit performed by a specialized & independent Organization* TaxPayers' Alliance, a British free-market lobby group* Tempe Preparatory Academy, a preparatory secondary school in Arizona, USA...
, plasminogen, and to a lesser extent alpha 2-antiplasmin
Alpha 2-antiplasmin
Alpha 2-antiplasmin is a serine protease inhibitor responsible for inactivating plasmin, an important enzyme that participates in fibrinolysis and degradation of various other proteins...
. The euglobulin fraction also contains factor VIII
Factor VIII
Factor VIII is an essential blood clotting factor also known as anti-hemophilic factor . In humans, Factor VIII is encoded by the F8 gene...
.
After precipitation, the euglobulin fraction is resuspended in a borate solution. Clotting is then activated by the addition of calcium chloride at 37 C. Historically, subsequent amount of fibrinolysis was determined by eye, by observing the clot within the test tube at ten minute intervals until complete lysis had occurred. Newer automated methods have also been developed. These methods use the same principle as the older technique, but use a spectrophotometer to track clot lysis as a function of optical density.