Kinetics of rouleaux formation using TV image analyzer

image analyzer. II. Rat erythrocytes. Am. J. Physiol. 245 (Heart Circ. Physiol. 14): H259-H264,1983.-With the use of a rheo-scope combined with a TV image analyzer, the kinetics of specific pathogen-free rat erythrocyte aggregation was studied. Under certain conditions (y 7.5 s-l, hematocrit 0.36%, in own plasma, at 25 O C) one-dimensional aggregates (rouleaux) were formed without the development of three-dimensional aggre-gates, perhaps because of very low concentration of y-globulin. The observed phenomena could be explained by 1) the eryth-rocyte sedimentation and 2) the rouleaux formation. The time courses, of the biphasic change in erythrocyte count and of the increments in total area and in the area/count, were success-fully simulated by a kinetic model of linear polymerization, assuming a sedimentation rate constant and an association rate constant. Further, a Poissonlike distribution of the length of rouleaux was shown, as predicted theoretically on the basis of the same kinetic model. aggregation; erythrocyte (specific pathogen-free Sprague-ley rat); shear rate; linea r polymerization; simul ation