Transmembrane defects were found to be formed in donor blood erythrocy
tes during their freeze-thawing in the non-penetrating cryoprotective
medium (0.13 M polyethylene. oxide with molecular mass of 1500 (PEO-15
00), 0.5 M sucrose). Permeability of erythrocyte membranes for ions of
Na+, Ca2+, Mn2+ and sucrose molecules also underwent changes. Reparat
ive processes were shown to restore membrane barrier properties.