Fig. 2.

(a) A schematic of the BAL chamber with representative pouch which contained cells. These pouches were nylon mesh, permeable to culture medium and ice but impermeable to ELS. This chamber was cooled from the edges (as indicated in purple), and ice developed radially to the central semi-circle, with the semicircles representing areas that solidified at the same time. The biomass fill is represented by the dotted black line. This pouch was extracted and dissected into 5 as shown on the right of the figure. These sections were thawed consistently to determine spatial differences in damage on cooling. This approximately replicated conditions in a vial shown in Fig. 1. (b) – the large chamber used for thawing experiments. This was cooled from the edges as the BAL chamber. 25 warming tubes were passed through the biomass (indicated in red), with ethanol equally distributed through each tube using larger endcaps. The opening at the top was used for addition and removal of vials, and was sealed prior to cryopreservation. Pouches were placed within 5 cm of either the inlet or outlet tubes, with pouches of cells nearer the warming inlet thawing more rapidly. Pouches were removed for viability studies on thaw. Both BAL set-ups had a diameter of 15 cm and length of 30 cm.