The purpose of GM mouse line cryopreservation is:

  • to protect against the loss of valuable strains through breeding failure, disease or genetic drift.
  • to eliminate the cost of maintaining mouse lines not actively in use.
  • to free up space for other mouse lines.
  • to facilitate future re-derivation.

Mouse Embryo Cryopreservation
Mouse embryo cryopreservation is currently restricted to FVB/N and C57BL/6N backgrounds. If other background strains are required, TCDM will need to test their viability. Approximately 300 embryos are collected and cryopreserved using a slow rate freezing method. Embryos are stored in straws submerged in liquid nitrogen, and divided between two tanks to prevent loss of lines in case of catastrophic failure. There is a yearly maintenance fee. The thaw-test is performed for embryos’ viability and fetus formation. The thawed embryos are transferred into pseudopregnant females. Upon completion of cryopreservation, we will notify you, and either return the males, or euthanize the remaining colony.

Mouse Sperm Cryopreservation
Archiving of mouse stocks by cryopreservation of sperm has great potential, because it is simple, rapid and cheap. Sperm cryopreservation only requires 2 sperm donor mice. The males are euthanized, sperm is collected from the cauda epididymis and cryopreserved in straws in liquid nitrogen. For further information, please contact TCDM.

Establishing a mouse colony from cryopreserved material
Establishing a mouse colony from frozen embryos is performed by thawing embryos and then transferring them in pseudopregnant females to develop to term.

For frozen sperm, In vitro fertilization (IVF) is performed after thawing of sperm sample. Resulting embryos are transferred in pseudopregnant females to develop to term.