Rederivation Solutions Built Around Your Needs
We offer multiple approaches:
- IVF rederivation
- Embryo transfer
- Ovary transplantation
Trusted Expertise, Transparent Expectations
Rederivation success depends on factors such as strain background, sample quality, and the cryopreservation method used by the originating institution. While our team applies rigorous standards and deep experience, individual recovery rates or genotypes cannot be guaranteed.
Import of Frozen Material
Importing cryopreserved sperm or embryos is streamlined with VGER. With prior DAC approval, you can easily bring in valuable lines from external sources. Getting started is simple:
In Vitro Fertilization (IVF)
Applicable to: External lines (frozen sperm) • Vanderbilt lines (fresh or frozen sperm)
IVF is the preferred and most efficient rederivation method. Frozen or fresh sperm is used to fertilize oocytes from superovulated wild‑type females. The resulting 2‑cell embryos are transferred into recipients the next day. Pups are born ~19 days later, and tail biopsies are provided at 3 weeks for genotyping before colony establishment.
Benefits: High throughput, reliable recovery, and excellent for both cleaning lines and rapidly expanding colonies.
Line Expansion by IVF
Applicable to: Vanderbilt lines only
To rapidly expand a colony from a single founder, sperm from N1 heterozygous males is used to fertilize multiple wild‑type oocytes. Approximately half of the N2 offspring will be heterozygous, enabling immediate generation of experimental cohorts. This strategy can save multiple generations of breeding time.
Embryo Transfer (Fresh or Frozen Embryos)
Applicable to: External lines (fresh or frozen) • Vanderbilt lines (fresh or frozen)
Fresh or cryopreserved embryos (0.5–3.5 days old) are extensively washed and transferred into recipient females. Pups are delivered 17–19 days later. Tail biopsies are provided at 3 weeks of age for required genotyping.
Note: For external sources, embryos can be shipped at 2‑cell through blastocyst stage.
Embryo Retrieval and Transfer
Applicable to: Vanderbilt lines
Embryos are collected directly from donor females, cleaned, and transferred into recipients. This method is ideal for protecting at‑risk or poor‑breeding lines while maintaining genetic integrity.
Ovary Transplants
Applicable to: Vanderbilt lines
For irreplaceable lines that have stopped breeding, ovaries from a transgenic female are transplanted into recipient animals to preserve the genotype. This rescue technique is rarely needed but essential for preventing loss of critical strains.