Summary
Plasma components were visualized in three-dimensional detail by a method which depends
on attaching plasma components, including platelets and fibrin, to a siliconized surface
where they can be fixed, dehydrated and shadowed. Citrated PRP and blood contained
a mixed population of discoid and dendritic platelets. Discoid platelets were thin
with gently changing elevations and depressions on their surfaces. Dendritic platelets
exhibited a random number and arrangement of dendritis. The “bodies” of dendritic
platelets appeared to be thicker than discoid platelets. After thrombin action, the
“bodies” from which dendrites radiated resembled various irregularly shaped geometric
forms whose thickness was approximately equal to their width. Continued thrombin action
caused disintegration of platelet membranes.
Fibrinogen could not be resolved. However, after thrombin action, extensive polymerization
of fibrin monomers into protofibrils about 130 Å wide was observed well before appreciable
lateral or vertical polymerization had occurred. Later, large strands with frequent
points of Y-type branching were common.
The method has clinical potential since the entire procedure is simple and can be
completed in less than an hour.
