Comparing techniques: the use of recalcified plasma in comparison with citrated plasma alone and in combination with thrombin in ultrastructural studies.

Fibrin plays a vital role in the coagulation process and fibrin fiber morphology can be studied using ultrastructural techniques. When studying the ultrastructure of fibrin networks, thrombin may be added to the plasma, ensuing fibrin network formation. The question that arises is whether there are differences in morphology when thrombin is added to plasma, versus morphology observed when plasma from citrated or recalcified citrated whole blood, is studied. The current study therefore aimed to compare ultrastructure of platelets and fibrin networks from these three techniques. Results indicated comparable platelet ultrastructure between smears formed from the plasma of citrated blood and that of the citrated recalcified blood. This method might give us further information regarding the 'natural state' fibrin assembly and association with platelets, when studying haemostasis. However, when studying the ultrastructure of fibrin networks, the addition of thrombin is necessary to form an expansive, fully coagulated layer of fibrin fibers.