Liquid nitrogen has many uses, mainly based on its cold temperature and low reactivity. Examples of common applications include:
The freezing and transporting of food products
The cryopreservation of biological samples, such as sperm, eggs, and animal genetic samples
Use as a coolant for superconductors, vacuum pumps, and other materials and equipment
Use in cryotherapy to remove skin abnormalities
The shielding of materials from oxygen exposure
The quick freezing of water or pipes to allow work on them when valves are unavailable
A source of extremely dry nitrogen gas
The branding of cattle
The molecular gastronomy preparation of unusual foods and beverages
The cooling of materials for easier machining or fracturing
Science projects, including making liquid nitrogen ice cream, creating nitrogen fog, and flash-freezing flowers and subsequently watching them shatter when tapped onto a hard surface.