Fig. 2. Cryoinjury to R. sylvatica erythrocytes frozen at -4 or -6°C in PBS (no urea) or PBS containing 40 mmol l^-1 urea or 80 mmol l^-1 urea. Damage was assessed as the percentage of total LDH leaking from cells and as the percentage of cells lysing. Within temperature-treatment groups, mean values (± S.E.M., N=6-7 replicates per group) identified by different letters differed significantly (repeated-measures ANOVA/Bonferroni; P<0.05).