Sperm Cryopreservation
Information about the long term storage of transgenic lines through sperm cryopreservation
CTC offers a free sperm cryopreservation contingency program that is open to all University of Edinburgh researchers. Our aim is to protect each and every transgenic allele through sperm cryopreservation. We recommend that upon the import or generation of a new transgenic line, males are set aside for the cryopreservation program.
The sperm frozen under the cryopreservation programme is not intended for global distribution. If a line is expected to be popular with a lot of distribution demand, we recommend that additional sperm is frozen at a repository such as the European Mouse Mutant Archive - EMMA.
Although CTC can freeze rat sperm, at this time CTC cannot revive rats from frozen sperm by ICSI or IVF.
Researcher's responsibilities during process:
- Identify 2 mature (2-6 month old), proven (i.e. they must have produced a pregnancy) males per line to be cryopreserved.
- Ideally, ensure that your chosen males transmit the desired genetic modification.
- Complete the ‘Sperm Cryopreservation Request Form’ (see below) and return it to CTC.
CTC’s responsibilities during process:
- Sperm will be collected and assessed for motility and concentration of motile sperm prior to and post freezing.
- If sperm quality is sub-optimal, CTC will request another male.
- CTC will typically store approx. 16 straws per line (8 per male).
- A proportion of lines frozen will be verified for quality assurance by performing IVF.
- If a researcher requires quality assurance of specific lines to validate recoverability, this can be requested and paid for by the researcher. This is recommended by CTC before a researcher completely closes a colony on the shelf. Please contact the CTC manager for further information.
