Sperm Cryo Kit frequently asked questions

What does this mean: "The kit can be used to cryopreserve strains that can be recovered on the following inbred or hybrid genetic backgrounds: C57BL/6, DBA/2, C3H/He, FVB, B6C3F1, and B6129SF1"?

It means that you will need to select one of the 6 background strains offered for the quality control step 2 of your sperm samples.  We suggest that you select the strain that best matches the genetic background of your strain. For most knockout and transgenic mice on a mixed B6:129 background, we suggest using C57BL/6J as the oocyte donor. If you need help selecting the most appropriate strain, please contact us.

The number of strains I have to cryopreserve doesn't exactly fit the number of strains offered in your 3-strain, 6-strain and 9-strain kit configurations. Does the kit come in any other size?

Currently, the kits are only offered in these configurations.If you have fewer than three strains to cryopreserve, you may want to consider using our Sperm Cryopreservation Service.

I want to cryopreserve 27 or more strains. Can you send me a larger kit than the 9-strain kit, and do you offer a bulk discount?

When you order three or more 9-strain kits for shipment at the same time, we offer a 10% discount of the combined purchase price.

Can I purchase individual components of the kit separately, such as the cryopreservation apparatus, the media or labeled straws?

No. Kit components are not sold separately.

If I store my kit samples at JAX, will my strains and information remain private?

Yes. Your samples are your property and all information you provide to us is kept highly confidential. If you are interested in donating your strains to the public, please see our information on donating a strain to The Jackson Laboratory, our Sponsored strain distribution servce or contact jaxservices@jax.org.

After cryopreservation is complete, for how many years is the sperm viable?

Once the sperm are in liquid nitrogen, if they have been handled properly, they should be viable and stable indefinitely. JAX has recovered cryopreserved mouse sperm (using older methods) after 10+ years and frozen embryos after 30+ years. Theoretical calculations indicate that samples should not degrade significantly with the passing of time.

Can I use the kit to cryopreserve sperm from other mammalian species?

No, it is designed to work only with mice. Please do not send us anything other than cryopreserved mouse sperm in the straws provided.

I've never dissected a mouse epididymis or vas deferens before. How difficult is the technique?

Accurate dissection of the epididymis and vas deferens is critical to successful sperm cryopreservation. The Sperm Cryo Kit manual provides an illustrated guide for this dissection but is not meant to replace requisite training. We recommend that you obtain training in this technique and practice prior to using the kit for your unique strains.

How do I best ensure I achieve success when I use the kit?

Obtain training in epididymis and vas deferens dissections from an experienced colleague. Follow the instructions in the manual, paying special attention to the critical elements and time-sensitive steps. Use the practice set of straws and cassettes. Use male mice within the recommended age limit, 10-16 weeks of age, because sperm from mice of this age range yield the best IVF success rates. Finally, as an alternative to the kit, consider having JAX perform the sperm cryopreservation step for you through JAX® Sperm Cryopreservation Service.

Additional services

Can JAX thaw sperm from my kit samples and ship live mice to me or my collaborator?

Yes. Contact jaxservices@jax.org to request information on Sperm Recovery.

Can JAX test the recovery of my mice to see if they develop to live born?

Yes. After you purchase your kit, you can ask your assigned Project Specialist or contact jaxservices@jax.org about this additional service.

Does JAX offer a course where you can teach me how to cryopreserve sperm using the kit?

Yes. Through our JAX Courses and Conferences division, our Reproductive Scientists annually offer a course where we cover methods and have hands-on lab work cryopreserving mouse sperm using our published methods. Please ask your regional JAX representative if interested in hosting an on-site training workshop.

Sample shipping

When should I send back my frozen sperm samples?

You should plan to ship your cassettes back to the Jackson Laboratory as soon as possible after completing the cryopreservation to more quickly obtain QC results about the cryopreservation success and to ensure safe storage of your samples. Ideally, samples should be cryopreserved and cassettes loaded into the dry shipper the same day, and shipped back to JAX the same day or the next day. If needed, cassettes can be stored temporarily in your own liquid nitrogen tank.

How do I order a dry shipper?

Approximately 10-14 days prior to the day you plan to ship your cryopreserved sperm samples to The Jackson Laboratory, contact your Project Specialist to request a LN2 dry shipper. The dry shipper will arrive charged and ready to ship the cryopreserved samples. Sperm samples should be collected, cryopreserved, and transported to The Jackson Laboratory within three days after receiving the dry shipper.

How do I know that the dry shipper is charged and safe for my samples?

The dry shipper will arrive charged. When opened, the interior of the shipper should appear to be cool; if not, contact your assigned project specialist. It’s imperative that you ship the cassettes in the dry shipper within three days of arrival at your facility. The shipper is designed to hold its charge for the duration of the transportation time to and from your facility.

Can I ship the dry shipper back to you any day of the week?

Yes, you can ship the dry shipper on any day of the week. The Jackson Laboratory can receive dry shippers on any day of the week, including Saturday and Sunday.

Do I have to ship all 20 straws for each strain back to you?

We strongly recommend that you do so. Our storage service will place your samples in three different tanks in two different locations. If we receive fewer than three cassettes, we can't distribute your samples among each of the three tanks. Note that straws from one of the cassettes are used for the IVF quality control check.

At some point in the future, can you send straws back to me or to a collaborator?

Yes. There would be a cost for retrieval of your straw(s) and preparation of the shipment, plus use of a dry shipper and freight costs.

Media

How should I store the media?

Upon receipt, store cryoprotective media (CPM) at -80°C. Once CPM is thawed, do not refreeze. Once thawed, the media should ideally be used the same day. If absolutely needed, the media can be stored at 4°C for up to seven days, although storage at 4°C is not optimal. Be sure to warm CPM to 37°C and shake to dissolve any precipitate prior to use.

Where can I buy the media?

The media is not commercially available. The method for making media is described in Ostermeier GC, Wiles MV, Farley JS, Taft RA. 2008. Conserving, Distributing and Managing Genetically Modified Mouse Lines by Sperm Cryopreservation. PLoS ONE 3(7): e2792 doi:10.1371/journal.pone.0002792.

When does the media expire?

Media is stable for three months at -80°C. The kit should be used within this timeframe.