Cracking in a vitrification solution during cooling or warming does not effect growth of cryopreserved mint shoot tips

No obvious decrease in viability or in the ability of mint shoot tips to develop into a shoot occurred during vitrification when the external glass cracked upon either cooling or warming. Samples within semen straws did not show a decrease in survival over three cycles of cooling and warming either in the presence or absence of cracking. No physical defects were visible in treated shoot tips. Cracking of the external glass formed from PVS2 did not obviously influence shoot tip survival in mint species.