A cryobank is a medical facility that stores a wide variety of tissues and cells in a state of deep freeze. Some cryobanks store human samples such as stem cells that are later used for research or treatment of various types of cancers. Many facilities specialize in fertility, and freeze either or both sperm and eggs in order to be used later.
These facilities typically have a cryopreservation unit, which is used for the actual storage of the materials. Many use liquid nitrogen to preserve the tissues or cells, which lowers the temperature below freezing and keeps the cells viable for research or other applications. In the case of reproductive tissues, these are kept viable for future implantation in women trying to get pregnant.
Materials are carefully prepared before they are put through the freezing process, in which water molecules within the samples are frozen. There is typically a loss of some tissues, but the majority of the sample remains intact for as long as it is frozen. Since purity of each sample is of vital importance, most cryobanks do not put the liquid nitrogen in direct contact with the sample in order to freeze it. Instead, samples are put in freezers and kept separate from the liquid nitrogen, frozen by the temperature of the environment instead.
Many cryobanks also have a laboratory where scientists or researchers prepare the samples for freezing. Before being frozen, samples are kept sterile and free of bacteria that could make them unusable. When reviving the samples, bringing them back from the freezing process is a delicate procedure that requires sanitary conditions in order to maintain sample integrity. There is often also a portion of the cryobank's laboratory set up to grow cell cultures from those that have been preserved.
Many facilities specialize strictly in sperm and egg donations. Donations can be anonymous, and preserved until a suitable match is found. Alternately, those serving in the military or in high-risk jobs can choose to have their genetic material frozen and stored in cryobanks in case something happens to them; this way, the family line can be carried on after death.
Researchers, scientists, and medical professionals are constantly developing new ways to use cryobank facilities. In addition to preserving genetic material and stem cells for research, some facilities are also used to preserve other endangered tissues. Coral reefs are in danger of disappearing, and scientists have even used cryobanks to store samples of different types of coral in order to help ensure their survival.