Coagulation laboratory tests
Thrombin time

Author: Jeremy Parsons, M.D. (see Authors page)

Revised: 17 May 2016, last major update November 2012

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Thrombin time [title]

Table of Contents
Definition / General
Cite this page: Thrombin time. website. Accessed October 26th, 2016.
Definition / General
  • Measures rate of fibrin clot formation after addition of standard concentration of thrombin to citrated plasma (Key, Makris, O'Shaughnessy and Lillicrap (Eds): Practical Hemostasis and Thrombosis, 2nd Edition, 2009 (Page 53))
  • Thrombin cleaves fibrinogen, releasing fibrinopeptides A and B, converting fibrinogen to fibrin
  • Useful to diagnose dysfibrinogenemia after more common disorders are excluded

  • Reference range: 10 - 13 or 16 - 24 seconds, depending on reaction conditions and thrombin concentration

  • Prolonged if even small amounts of heparin, hirudin or argatroban anticoagulants are present
  • Also prolonged with dysfibrinogenemia, amyloidosis (inhibits fibrinogen conversion to fibrin), DIC, thrombolytic therapy or thrombin inhibitors in patients exposed to bovine thrombin