Semen cryopreservation is a vital reproductive technology used to store sperm in liquid nitrogen for long-term storage, enabling artificial insemination, genetic improvement, and widespread distribution of superior genetics. It involves semen collection, dilution with extenders containing cryoprotectants (like glycerol), cooling, packaging in straws, freezing, and thawing, although this process causes inevitable cryo-injury to sperm cells.
Key Aspects of Semen Cryopreservation:
- Purpose: The primary purpose is to store superior semen for long periods (indefinitely) for international trade and breeding programs, as well as to prevent the spread of diseases.
- Process: Spermatozoa are collected (usually via artificial vagina) and immediately diluted with extenders. Extenders, commonly based on egg yolk or plant-based materials, provide nutrients, buffer pH, and protect the plasma membrane.
- Cryoprotectants (CPAs): Glycerol is commonly used to prevent ice crystal formation and protect sperm membrane integrity during freezing.
- Cryodamage: Despite optimized protocols, the process causes substantial damage to sperm, such as metabolic alteration, DNA fragmentation, and reduced motility. These include cold shock, osmotic stress, and oxidative stress from reactive oxygen species
- Post-Thaw Quality: Success is measured by motility, morphology, and fertility rates. Quality control is crucial to ensure only high-quality semen is used.
Bovine semen is typically cryopreserved in 0.25 mL straws. These straws are subsequently packed into goblets, which generally hold either 10 or 25 straws. To minimise the risk of human error and maintain product integrity, Just Genes purchased a Minitube Straw Packer. This machine automatically transfers the straws into goblets within a temperature-controlled environment maintained at approximately −190°C, helping to preserve sample quality throughout the packing process. Once packed, the goblets are prepared for long-term storage at Just Genes or for national or international shipment.
Just Genes has used this system successfully for many years, serving thousands of satisfied clients. Combined with our morphology testing and secure storage facilities, you can trust your samples are in expert hands
