Sperm Cryopreservation

To initiate an project, complete the request form found on the NUcore TTML page and upload when ready to purchase on NUcore.

• The NUCore submitted request form is reviewed and once approved, TTML staff will contact you to schedule cryopreservation. You will be required to confirm the name of the line(s) and the time/date of the scheduled cryopreservation. ***Please note: if we do not receive the males on the confirmed date/time, or receive males from a different line, additional costs will be charged.
• Two males ideally between 3-5 months of age, although older males are acceptable, for each line should be identified for cryopreservation.
• On the day of the cryopreservation, the males need to be transferred to the TTML animal protocol (which we will walk you through) and brought to our SQ lab (B-700) in a fresh cage with food and a water bottle at the scheduled time.
• Sperm is then isolated from both males, pooled and frozen into 20 straws.
• A test straw of cryopreserved sperm is thawed from each frozen line and QC performed to determine the quality of the sperm.

A minimum of 17-20 straws of frozen sperm is generated for each line. A test straw from each freeze is thawed to determine the success of the procedure.

Due to the pandemic, the QC of the cryopreserved sperm has been separated into two service options.

All frozen lines are routinely tested for viability and developmental capacity. In vitro fertilization (IVF) is performed with thawed sperm and wild-type B6J oocytes. Percent fertilization (the percentage of fertilized two-cell stage embryos generated during IVF) and development of IVF-generated embryos to blastocyst stage are good indicators that the line can be recovered successfully.

Option 1: The cost of option 1 is $525/line.

This service includes testing the fertilization capacity of the sperm. This option allows projects to move more quickly through the facility so that investigators can cull colonies sooner.

• IVF is performed with thawed sperm and wt B6 oocytes, as described above, and the percent fertilization is used to determine the viability and fertilization capacity of the sperm. These parameters are generally highly correlative with, although does not guarantee, the ability of the cryopreserved sperm to generate pups should recovery of the line be requested in the future.
• It is critical that you are confident in the genotype of the provided males. Tails samples are taken from the males at the time of the sperm collection and can be provided if requested.
• The project is complete if acceptable QC results are obtained. If the thaw test results are not acceptable, sperm from another set of males will be cryopreserved at no additional costs. 

Option 2: The cost of option 2 is $805/line.

In addition to the testing the fertilization capacity of the sperm, this option includes the testing of thawed sperm to live birth and must be requested during scheduling. 

• Investigators have the option of testing lines to live birth and confirming the genotype of recovered pups. For this service, IVF generated embryos are transplanted into foster mothers and tissue from d18 live pups is provided for genotyping.
• Your lab is notified when tissue is available for pick-up. Tissue samples are placed in a small -20ºC freezer just outside our SQ lab (B-700) and can be picked-up any time. Please sign the sheet on top of the freezer when collecting samples.
• Projects will be charge when genotyping is confirmed OR two weeks after notification that tissues are available for pick-up.

Cryopreserved sperm from each line is stored in two separate liquid nitrogen dewars in two different buildings.

There is a modist annual fee for each line maintained in our dewars.

Sperm can be cryorecovered at any time simply by contacting our lab.

Sperm can also be shipped worldwide from our lab.