Red blood cell adhesion. III. Analysis of forces.

The results of experiments on the adhesion of glutaraldehyde-fixed red blood cells to both polarizable metal/saline and liquid hexadecane/saline interfaces have been analysed in terms of physical forces. The results show that the electrostatic repulsions sufficient to prevent adhesion to these test surfaces are remarkably similar, and that a force-balance condition is predicted at cell-substratum separations similar to or approximately 100 nm in 0.4 mM NaCl as found by interferometry. From the repulsive force the size of the attractive force can be found. If this is viewed as an electrodynamic attraction, the force coefficient is found to lie between 5 and 8 x 10(-14) erg (5 and 8 x 10(-21)J), a range in reasonable correspondence with measurements in physical systems.