Euglobulin lysis time
{{Infobox diagnostic
| name = Euglobulin lysis time
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| test of = Overall fibrinolysis
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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, tissue plasminogen activator (tPA), plasminogen, and to a lesser extent α2-antiplasmin. The euglobulin fraction also contains factor VIII.{{cn|date=November 2021}}
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.
{{cite journal | first1 = E. | last1 = Kowalski |first2=M. |last2=Kopeć |first3=S. |last3=Niewiarowski | title = An Evaluation of the Euglobulin Method for the Determination of Fibrinolysis |journal = Journal of Clinical Pathology |volume=12 |issue=3 |pages=215–8 | year = 1959 |pmid=13654539 |pmc=479903 |doi=10.1136/jcp.12.3.215 |doi-access=free}} 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.{{cite journal |last1=Smith |first1=Amy A. |last2=Jacobson |first2=Linda J. |last3=Miller |first3=Brian I. |last4=Hathaway |first4=William E. |last5=Manco-Johnson |first5=Marilyn J. |title=A new euglobulin clot lysis assay for global fibrinolysis |journal=Thrombosis Research |date=January 2003 |volume=112 |issue=5–6 |pages=329–337 |doi=10.1016/j.thromres.2004.01.001 |pmid=15041279}}