Reduce costs associated with animal colony maintenance, while protecting valuable research strains by using our rat and mouse cryopreservation services. Mouse cryopreservation aids in limiting genetic drift, preventing loss of phenotype, and enables an easy recovery of VAF/Elite™ mice and rats.
Navigate Cryopreservation with Confidence
Learn best practices to secure your genetic line and reduce the risk of potential disasters.
Rodent embryos and sperm are divided between two independent locations, each with an automated liquid nitrogen filing system and an alarm network to help ensure the security of our clients' valuable animal models.
Animal lines can be recovered in as few as eight to ten weeks once cryopreserved stock is created. This quick recovery time ensures that potential interruptions to ongoing experiments due to animal loss are minimal.
Learn about navigating cryoservices with confidence.
Mouse Sperm Cryopreservation
Sperm cryopreservation is increasingly becoming a fast, safe, and cost-effective way to protect genetically engineered mouse colonies. With mouse sperm cryopreservation, it is feasible to cryopreserve stocks at multiple stages of model development (e.g., after creation or backcrossing), which provides an opportunity to recover a model from an earlier state if it ever becomes necessary. Our mouse cryopreservation for all genetically engineered mouse strains provides a permanent backup for valuable lines.
For some mouse models, sperm cryopreservation may not be the best way to protect a colony due to specific genetics, phenotype, or composition of the model. Our dedicated team of project initiation specialists works with each client to determine if their line is a good candidate for sperm cryopreservation and ensure the success of those that are.
When mice are submitted for sperm cryopreservation, sperm is collected from the caudal epididymis and vas deferens of the male reproductive tract, treated with a cryoprotective agent, aliquoted into straws, cooled, and stored in liquid nitrogen. We recommend cryopreserving sperm from at least two gene-carrier males.
Mouse and Rat Embryo Cryopreservation
Rat and mouse cryopreservation remains the easiest and safest method of long-term cell storage. To successfully cryopreserve a genetically engineered rodent strain, it is important to consider several factors, including:
- The percentage of thawed embryos that will carry the mutation
- The percentage of thawed embryos that will be viable
- The anticipated live birth/weaning rates following embryo transfer
The exact number of rat or mouse embryos that should be cryopreserved is influenced by the genotype of the animals being used, the background strain of the model, and any special characteristics of a specific lineage. We have decades of experience in freezing rodent embryos and regularly assist clients in determining the appropriate quantity to cryopreserve for each model.
Depending on the number of males provided, the background strain of the model, and the specifics of the genetic mutation, we will collect embryos either via live matings or in vitro fertilization (IVF). Embryo cryopreservation may also be combined with embryo transfer rederivation to achieve pathogen-free strains of animals.
Animals required for embryo cryopreservation may be bred with us or supplied at regular intervals from your facility. While here, all genetically engineered animal lines are housed within flexible film or semi-rigid isolators. The isolator not only guards against microbiological contamination, but also against genetic contamination by physically separating individual lines.
Procedures for embryo cryopreservation include collection of preimplantation-stage embryos, treating suitable embryos with a cryoprotective agent, loading the selected embryos into Cryotech™ straws, and freezing the embryos at a controlled rate.
• Emrbyo Cryopreservation: Mice and Rats
• Sperm Cryopreservation: Mice Only
• Cryopreservation with HO Breeding
How does mouse cryopreservation work?
The biological metabolism of living cells significantly decreases and eventually ceases at low temperatures, permitting the long-term preservation of living cells. There is an obvious contradiction between the concept of low temperature preservation and the fact that living cells can be damaged both by temperatures lower than the freezing point of water (0° C) and by the cryoprotective agent itself.
They key to successful mouse cryopreservation is to minimize the creation of harmful ice crystals during the freezing process to ensure that little or no intracellular ice forms. Furthermore, the cryoprotectant, designed to prevent ice formation, must be relatively nontoxic.
Equally important, the cells must be cooled gradually to ensure that they lose water slowly enough to dehydrate without freezing intracellularly, but quickly enough to avoid cell deterioration and death due to dehydration.
To overcome this challenge, we use internally developed techniques backed by years of experience in cryoservices that result in minimal cryoinjury and high cryosurvival rates.
How are cryopreserved mice and rat stocks shipped?
Cryopreserved animal stocks can be transferred from our facilities to another location using dry LN2 shippers.
To guarantee the integrity of the shipment, the LN2 shipper can be equipped with a data logger to ensure the temperature of the shipper has been maintained throughout transit. To further protect cryopreserved animal models, we recommend splitting the shipped material into two separate transfers, providing a redundancy in the event of a shipping delay.
After mouse cryopreservation, how are the preserved lines stored?
After mouse cryopreservation, it is important to maintain the frozen stock in a tightly controlled facility. We maintain two independent facilities that are equipped with bulk liquid nitrogen storage tanks and are monitored and alarmed 24 hours a day for tank temperature and LN2 level.
All cryopreserved rodent stocks are automatically split between the two storage facilities, providing redundant backup. We also routinely accept cryopreserved material frozen by our clients for storage. This service provides an offsite backup in the event that a client’s facility is compromised.