Summary
Clot retraction is reviewed as a visual experience from the elementary considerations
to more complicated and uncertain perspectives. The extent of retraction is dependent
upon temperature, cell volume, surface contact, pH, fibrinogen concentration, thrombin
concentration, calcium ion concentration, and platelet concentration. Platelets function
in their own unique way. This quality is lost by such treatment as dialysis, ultrasonic
waves, storage, and freezing. In the latter case there is some protection in glycerol
solutions. Plasma contains dialyzable material concerned with clot retraction. This
includes glucose and phosphorous, and perhaps other substances. Moreover, plasma contains
one or more proteins of interest in clot retraction, and this protein(s) can be adsorbed
on barium carbonate and eluted with sodium citrate solution. There may be clot retraction
without the dialyzable material of plasma if the nondialyzable protein(s) are present
and vice versa. The work is illustrated extensively with photographs and variables
are considered in terms of three dimensional projection. In addition the ideas reviewed
were developed in terms of information obtained with time lapse motion picture photography.
