Influence of a static magnetic field on the slow freezing of human erythrocytes.

Purpose: The aim of this study was to test whether or not a strong static magnetic field (SMF) had a positive effect on the survival rate of frozen erythrocytes.
Materials and Methods: Human erythrocytes were slow freezing at a rate of -1°C/min, to a final temperature of -20°C. During the freezing process, the cells were simultaneously exposed to an SMF with a magnetic induction of 0.2 or 0.4 T. After the cells were thawed, the survival rate, morphology, and function of the thawed erythrocytes were evaluated. Furthermore, tests of membrane fluidity were performed to assess the effect of the SMF on the cell membrane.
Results: The slow freezing process coupled with an SMF increased the survival rate of frozen erythrocytes, without any negative effect on the cell morphology or function. The increases in relative survival rates of frozen erythrocytes were 5.7% and 9.1% when the cells were frozen in 0.2 T and 0.4 T groups, respectively. In addition, the 0.4 T group significantly increased the membrane rigidity of the erythrocytes.
Conclusions: Slow freezing coupled with a strong SMF produced positive effects on the survival rate of thawed erythrocytes, without changing their normal function.