THE MECHANISM OF RED-CELL (DIS)AGGREGATION INVESTIGATED BY MEANS OF DIRECT CELL MANIPULATION USING MULTIPLE OPTICAL TRAPPING

We used multiple optical trapping to study the mechanism of red cell ( dis)aggregation. Two sets of optical 'tweezers' were used to bring two red blood cells together to form a two-cell aggregate and then to pul l them apart, to study the interaction between the cells. We found tha t cross-bridging occurred in normal reversible aggregation as we obser ved binding and the occurrence of small tethers between opposite cell membranes. Furthermore, the cells could only be parted by sliding them side by side with a maximum velocity in the order of mu m/s indicatin g accumulation of the cross-bridges.