Which of the following promotes rouleaux formation?
When in circulation, the negative charge on the RBC membrane (or zeta potential) does not allow RBCs to clump. When blood is made to stand in a veical tube, the asymmetric macromolecules in the plasma overcome the zeta potential, so as to form the rouleaux and settling down of the RBC clumps. Fibrinogen and gamma-globulins are the examples of such asymmetric macromolecules. Plasma albumin retards the rouleaux formation. Hence, in nephrotic syndrome, in which the albumin levels fall, there is a rise in ESR.
Zeta potential on RBC membrane
Fibrinogen
Albumin
Biconcave shape of RBC
Blood Physiology