ИСТИНА

Reversible aggregation is an intrinsic property of red blood cells (RBC) that determines the fluidic properties of blood and the hydrodynamic parameters resistance. The mechanisms of RBC aggregation are not fully understood so far. In order to assess them, the precise measurements of the forces generated in the process of aggregates formation are necessary. In this work, we report on the results of such measurements conducted with the help of laser tweezers (LT). We measured the interaction force between two RBC freely suspended in autologous plasma and initially having no contact for various overlaps. To do the measurements, the cells were trapped with LT and brought into contact. Then the LT were switched off and the cells started to crawl one onto another. After reaching certain fixed area of overlap the crawling was stopped with the LT. It was found that, the larger is the overlap, the higher is the force that should be applied to the cells by the tweezers to stop crawling, which we considered to be equal to the aggregating force (AF). The measurements were performed on blood samples of 9 healthy donors with averaging over 10 pairs of cells in each sample. It can be seen, that at larger overlaps the cells stronger bind to each other, which is a significant feature of the aggregation process.