Zeta potential

The electrical potential difference between red blood cells created by the surface negative charges on the red blood cells and the surrounding cations in the blood. This repulsive force prevents the RBCs from sticking together under normal conditions. Conditions that decrease this repulsion are typically relatively positively charged molecules which increases the chance of RBC agglutination (e.g. increased Ig levels as in Plasma cell Myeloma or changing the ionic strength when adding Low Ionic Strength Solution (LISS) in certain blood bank tests, etc.)