Single cell laser light scattering spectroscopy in a flow cell: repeated sickling of sickle red blood cells.

We performed dynamic laser light scattering measurements of hemoglobin aggregates in single, sickle erythrocytes. Sickle erythrocytes were attached to the poly-(L-lysine)-coated surface of a flow cell. They were exposed to several oxygenation-deoxygenation cycles by repeatedly changing the flowing solution. The rate of cycling was found to be a determining factor for the formation of irreversible morphologic alterations as well as irreversible hemoglobin aggregates. In slow cycling, the sickle erythrocytes took an irreversible, irregular, rounded shape, and hemoglobin aggregates were observed even in the oxygenated state after 20 cycles. In the fast cycling, however, these changes did not take place even after 60 cycles.