Cryogenic refrigerant is a gas that is used in the process of cooling materials that acts as the key component in the process of cryogenic freezing. This process turns gases that would otherwise remain gaseous at natural temperatures into liquids, making them easier to transport in large quantities.
A commonly used cryogenic gas is nitrogen, which comes into use in cryogenics in its liquid form. Liquid nitrogen finds a wide variety of uses in industry and scientific study - and even as an esoteric tool in the food industry. It is often used in the preservation of blood or other biological samples.