Theoretical analysis of unidirectional intercellular ice propagation in stratified cell clusters

A recently published theoretical analysis of intercellular ice propagation in stratified cell clusters comprising concentric spherical layers, by Zhang, Xu, Sandison, and Zhang [Cryobiology 47 (2003) 143], has been examined and is shown to be flawed. New equations are derived subject to simplifying assumptions implicit in the theoretical model presented by Zhang and co-workers. The conclusion by Zhang and colleagues that intercellular ice propagation can be assumed to be instantaneous is demonstrated to be invalid.