On magnetic orientation of red blood cells : differences between suspension in plasma and serum

The magnetic orientations of human red blood cells (RBCs) were investigated under strong magnetic fields up to 8 T by measuring electrical resistivity of suspensions containing RBCs. The electrical resistivities of the suspensions were decreased by application of magnetic fields parallel to the electric field. This phenomenon indicates that RBCs are redirected by a magnetic field. It was observed that the degrees of magnetic orientation of RBCs are different due to the medium surrounding RBCs such as plasma, serum or phosphate buffer solution. The changes in electrical resistivity of samples of 40% RBCs suspended in phosphate buffer solution, serum and plasma were 15%, 8% and less than 4% respectively. The electrical resistivity of anticoagulated whole blood was not changed by application of magnetic fields up to 8 T. These results show that albumin, globulin, fibrinogen and leukocyte prevent the magnetic orientation of RBCs in blood