Cryopreservation is an abbreviation for “cryogenic preservation.” Cryopreservation is the process of preserving cells and tissues that have not been damaged by subjecting them to extremely low temperatures. In most cases, the temperature of the samples is maintained at −196°C.
Because of the extremely low temperatures, the cells’ biological processes are put on hold. Cryopreservation allows cells to withstand the effects of freezing and thawing. Ice crystals can form inside the cells, which threatens the integrity of the cell membrane. This can be avoided by controlling the rate at which the biological material freezes and being careful when selecting the freezing media.
The Process of Cryopreservation
To preserve the viability of biological materials such as embryos, organs, organelles, oocytes and sperm, these materials are stored at extremely low temperatures without harming the cell’s capacity to function. Cryopreservation aims are halting any enzymatic or chemical activity that could potentially cause damage to the biological material in question.
During this process, the commonly used coolants are liquid nitrogen and dry ice (carbon dioxide at -80°C).
Here are the steps followed during cryopreservation.
Steps Followed During Cryopreservation
1. Collection/Harvesting of Biological Material – The volume, density, pH, shape, and damage-free nature of biological materials must be considered when selecting them.
2. Cryo-Protectant Addition – To keep samples from crystallizing by decreasing the freezing point of the medium and permitting a slower cooling rate sugar, salt, glycol or other cryoprotective chemicals are used.
3. Freezing – During the cryopreservation process, a number of different freezing methods are utilized to preserve the cells from the damage and death that would otherwise result from them coming into contact with heated solutions and warm solutions containing cryoprotective substances.
4. Cold Storage in Liquid Nitrogen – Before being transferred to the final storage containers, the cryopreserved samples must be kept in a liquid nitrogen freezer at a temperature of -196°C for at least 5 to 24 hours.
5. Thawing – This is the process of controlling the freezing rate of the biological samples. Thawing is essential for achieving the highest level of cryopreservation and recovery. The process of thawing is done to prevent the damage that crystallization can do to the cells.
The Advantages of Cryopreservation
- Delaying Pregnancy – Allows women to delay having children until they are in their 30s or early 40s
- Prevents illness and microbial contamination of the samples
- Ensures the genetic integrity of priceless stains is not compromised
- Treatments for infertility
- Prevents the genetic change of gametes, stem cells, embryos, etc.
- Safeguards from genetic contamination
- The shelf life of biological samples is extended significantly
- Conserves the genetic material of threatened species
Various Uses for Cryopreservation
There is a vast range of applications for cryopreservation. Some of the typical uses are:
- Preservation of excess embryos that are produced through IVF
- Profound hypothermia
- Cell culture preservation
- Blood bank
- Organ transplantation
- Storage of rare germplasm
- Conservation of highly endangered plant species
- Artificial insemination
- In vitro fertilization
- Gene bank
Knowing about cryopreservation is important, especially if you are considering freezing your eggs or sperm. It is a process that can help you to have a baby later in life, and it can also help to preserve the cells and tissues of people who are suffering from a terminal illness.