Abstract
The diffusion coefficient of erythrocytes was measured using quasi-elastic light-scattering (QELS) techniques. The cells were suspended in phosphate-buffered saline solutions with and without a macromolecule, polyvinylpyrrolidone (PVP[360]). In the presence of the PVP(360) an anomalously high diffusion coefficient was measured for metabolizing cells with a normal transmembrane potential. The results are in agreement with experiments on rouleau formation by red blood cells and are supportive of the hypothesis of a long-range coherent interaction between metabolically active biological cells.