Topics:
Animal Refresher, Animal Reproduction
Cryogen and Cryoprotective Agent in Frozen Semen
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Question (English)
Most commonly used cryogen and cryoprotective agent in frozen semen are respectively:
- LN₂ and Glycerol ✓ Correct
- Glycerol and LN₂
- Dry ice and LN₂
- Dry ice and Glycerol
Explanation:
Correct Answer: LN₂ and Glycerol
In frozen semen technology, Liquid Nitrogen (LN₂) is the most commonly used cryogen (the freezing agent/storage medium) and Glycerol is the most commonly used cryoprotective agent (CPA — protects sperm from freeze damage).
Role of Each
- LN₂ (Liquid Nitrogen): Provides the ultra-low temperature environment (–196°C) for long-term storage. Inert, non-toxic to cells, and maintains temperature stably.
- Glycerol: Penetrates sperm cell membrane and prevents intracellular ice crystal formation during freezing by depressing the freezing point and vitrifying the cytoplasm. Typically added at 6–7% concentration in bull semen extenders.
Other Cryoprotective Agents Used
- DMSO (Dimethyl Sulfoxide) — used in some species
- Ethylene glycol — used in vitrification protocols
📚 About this Topic — Animal Refresher
This multiple choice question is from Animal Refresher, Animal Reproduction. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Refresher to strengthen your preparation.
