JAX® Mice Cryopreserved Embryos - frequently asked questions
Embryo Information - Training
Are there books that may help me learn embryo transfer?
Yes: "Manipulating the Mouse Embryo," available from Cold Spring Harbor Laboratory Press.
Do you know where I could receive training for thawing straws and transferring embryos?
We highly recommend that you attend an Embryo Handling Workshop. There, you will learn how to thaw and transfer embryos. Furthermore, you will receive additional support when you return to your lab. The workshops are held in May and September at The Jackson Laboratory. See our listing of current courses for more details.
How will attending an Embryo Handling Workshop help me?
We will teach you how to collect, thaw, and transfer embryos, and we will give you additional help and support when you return to your lab. See our Courses and Conferences website for details on upcoming Embryo Handling Workshops.
Would someone from The Jackson Laboratory talk me through the embryo transfer procedure on the phone?
No. If you need help with transferring embryos, we strongly recommend that you take the Embryo Handling Workshop offered here. See our Courses and Conferences website for details.
Embryo Information - Receiving
Can I use the shipper to store my embryos until I am ready to transfer my embryos?
No. The dry shipper is for transport only. Embryos should be transferred to a permanent storage container immediately.
Do I need a liquid nitrogen supply at my facility?
Yes. You will need to transfer samples to a permanent storage container.
We have received a shipper to send our embryos to The Jackson Laboratory. Do we have to fill it with Liquid Nitrogen before sending it?
No. The shipper is pre-charged with liquid nitrogen. Simply put your embryos in the shipper, and make sure the embryo information is attached to it.
How do I know the dry shipper has not been opened or tampered with in transit?
The security ties, plastic wire ties on the outside and inside catches of the container, should still be in place when the shipper arrives.
How long can the samples be exposed to air when moving them to a storage vessel from the dry shipper?
No more than 5 seconds for straws and 30 seconds for vials.
I received a shipper with my samples enclosed, but where is the information about what I received?
An envelope in the lid of the dry shipper contains all the information you need. If it is missing, please email jaxservices@jax.org.
There is no liquid nitrogen in the shipping container. Will my samples still be OK?
The shipping container is a "dry shipper:" the liquid nitrogen is in the walls. Your samples are quite safe, but move them to a permanent storage container immediately.
What do I do with the dry shipper when my samples have been removed?
Please return to:
The Jackson Laboratory
Building G145
Attention: Kurt Christiansen
600 Main Street
Bar Harbor, ME 04609
Embryo Information - Transfer
Can I culture my embryos before transferring them into the uterus?
We don't recommend it. Transfer them immediately after they thaw.
Can I get practice embryos from The Jackson Laboratory before I order important strains?
Yes. We can supply practice embryos on request. Email jaxservices@jax.org.
Do you guarantee that we will recover mice from your frozen embryos?
No. We guarantee that we have successfully recovered all the strains available for sale, but we cannot guarantee that you will have similar results.
How long can I wait between thawing embryos and transferring them?
Transfer two-cell embryos within an hour of thawing them. You can thaw eight-cell embryos and keep them in a refrigerator for 3-4 hours before you transfer them.
Is timing critical when thawing embryos?
Yes. You should follow the protocol carefully.
Should I transfer all the embryos I recover?
If you are not experienced in grading embryos, you should transfer all of them-- even the ones that are not perfect.
Should I transfer embryos to a 0.5- or a 2.5-day pseudopregnant female?
Transfer 2-, 4-, and 8-cell embryos to a 0.5-day pseudopregnant female. A 2.5-day pseudopregnant female is used for transferring blastocysts.
Should my facility have a pseudo colony?
Ideally, yes, but you can vasectomize males and start your own.
If I do not recover any live mice from the practice straws, should I request more practice straws?
Yes. Please do not thaw out any strains received until you have successfully recovered the practice embryos. Email jaxservices@jax.org.
What media do I need to thaw embryos?
PBS for thawing vials and M2 for thawing straws. You will find the information on our web page, "Cryopreservation Media Preparation."
What strain do you use for pseudopregnant females?
Many hybrids and outbreds can be used successfully to make pseudopregnant female mice. We use CByB6F1/J (Stock number: 100009) animals.
