Nitrogen, or molecular nitrogen (N2), is a widely distributed gas in our atmosphere. It is naturally occurring in the environment and is not harmful. Nitrogen is odorless, colorless, and tasteless in its gaseous and liquid forms.
Liquid nitrogen turns into a gaseous state at -196°C under normal atmospheric pressure. In liquid form, liquid nitrogen has low viscosity.
There are a growing number of industries that make use of liquid nitrogen in a variety of different capacities. In biomedicine, for instance, a wide variety of cryogenic and cooling processes call for the utilization of liquid nitrogen since it can reach sufficiently low temperatures (much below the temperature at which water freezes) while in the liquid state.
The following is what you should know about liquid nitrogen in biomedicine.
Facts About Liquid Nitrogen
- Since liquid nitrogen does not need to be pressurized to release its nitrogen gas, it provides a source of dry nitrogen gas that is both portable and convenient to use.
- Liquid nitrogen is manufactured commercially. The process of fractional distillation of liquid air results in the production of liquid nitrogen. Similar to nitrogen gas, it is made up of two nitrogen atoms bonded to one another by covalent forces (N2).
- Nitrogen has no odor, no color, or toxicity. It does not support combustion and is relatively inert.
- When liquid nitrogen is stored, it is kept in specially designed and insulated containers equipped with vents to prevent pressure from building up inside. It is possible to store it for a few hours or for as long as a few weeks in an ln2 freezer, but it all depends on how the freezer is designed.
- Liquid nitrogen (LN2) exhibits the Leidenfrost effect, which indicates that it boils at such a high rate that it coats whatever it comes into contact with in a layer of nitrogen gas that acts as an insulator. This is the reason why nitrogen droplets will skitter across a floor if they are accidentally spilt.
Applications of Liquid Nitrogen in Biomedicine
Because of its low reactivity and extremely low temperature, liquid nitrogen can be utilized in a wide variety of contexts. The following are some examples of common applications of liquid nitrogen in biomedicine:
- Treatment of common skin conditions through cryotherapy. Cryotherapy is a treatment that eliminates tissue by subjecting it to extremely low temperatures. Liquid nitrogen is frequently used to treat skin lesions, growths or patches on the skin that do not appear to be similar to the skin in the surrounding areas.
- Cryogenic preservation of biological resources for later use; examples include sperm, eggs, and genetic material from human beings and animals. When temperatures are low, the genetic change, enzymatic and chemical activity of the cell is inhibited, which lowers the risk of the cell being damaged or contaminated.
- Brain cryosurgery (removing damaged or dead cells from the brain). Using liquid nitrogen during brain surgery makes removing tumors from the brain, spinal cord, and orbit easier. It minimizes the amount of blood loss that occurs due to vascular tumors.
- Palliative care for cancer patients. Cancer cells are more susceptible to cold temperatures than healthy cells. Thus, cryotherapy can be used to destroy cancer cells while leaving healthy cells unharmed.
- Treating warts and other skin conditions. Warts are growths on the skin that are caused by the human papillomavirus (HPV). They can be painful and unsightly. Cryotherapy can be used to destroy the HPV virus and thus get rid of the wart.
- Research purposes, such as for cryopreservation of cells and tissue samples.
Safety Precautions When Handling Liquid Nitrogen
Given that liquid nitrogen is extremely cold, it is important to take the necessary precautions to avoid injuries. The following are some safety tips to keep in mind when handling liquid nitrogen:
- Wear appropriate personal protective equipment (PPE), such as gloves, face shields, and protective clothing.
- Do not touch liquid nitrogen with your bare skin.
- Do not store liquid nitrogen in an unventilated area.
- Avoid inhaling the vapors from liquid nitrogen.
- Keep containers of liquid nitrogen away from heat sources.