How RBCs move through thixotropic gels

The purpose of this study was to describe the mechanism by which RBCs move through a thixotrophic gel during centrifugation of blood specimens. We dev eloped a system for direct observation and high-speed recording of images d uring centrifugation of blood in circular specimen containers (RD01 PlasmaR otor; StatSpin, Norwood, Mass). Observations were also made in conventional Vacutainer SST [serum separator tube] blood collection tubes (Becton Dicki nson, Franklin Lakes, NJ). Most of the RBCs moved in homogeneous formations through the central portion of the gel, and some moved between the gel and the inner wall of the tube. After the centrifugation process had separated RBCs from plasma, the thixotropic gel interposed between RBCs and plasma c ontained small micelles of RBCs, and a small collection of cells remained o n the surface of the gel. Our observational technique may be used to examin e factor that affect the process by which RBCs move through gels, including altered RBC structure in disease states.