Related Experiment Video
Updated: Jun 19, 2026

Experimental and Imaging Techniques for Examining Fibrin Clot Structures in Normal and Diseased States
Published on: April 1, 2015
STUDIES IN BLOOD COAGULATION : V. THE COAGULATION OF BLOOD BY PROTEOLYTIC ENZYMES (TRYPSIN, PAPAIN)
1Department of Bacteriology, School of Medicine, University of Pennsylvania, Philadelphia.
Abstract:
Crude or crystalline trypsin in proper concentration causes the blood or plasma of human beings, dogs, rabbits, guinea pigs, and horses to coagulate. It does not clot the fibrinogen directly, but reacts with prothrombin to form thrombin. Since trypsin thus has the same effect as the physiological system Ca plus platelets (or Ca plus tissue extracts), it is suggested as a tentative working hypothesis that the latter system contains a proteolytic enzyme with a specific affinity for prothrombin. Other implications of this trypsin effect with respect to the mechanism of physiological coagulation are discussed in the text (pages 557-558). The proteolytic enzyme papain also coagulates blood. In this case the enzyme does not activate prothrombin, but acts directly on fibrinogen to form a fibrillar gel resembling fibrin. If one admits this clot to be fibrin, this constitutes strong evidence that thrombin, the physiological coagulant, is also a proteolytic enzyme with a specific action on fibrinogen.
More Related Videos
09:38A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
Published on: February 14, 2017
06:16Tracking Fibrinolysis of Chandler Loop-Formed Whole Blood Clots Under Shear Flow in An In-Vitro Thrombolysis Model
Published on: April 19, 2024
Related Concept Videos
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Coagulation
During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions...
Coagulation
Clot Retraction and Fibrinolysis
Introduction to Hemostasis
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized, and...