Cryopreservation and lyophilization are two prominent methods for preserving delicate biological substances and pharmaceuticals for a long duration of time.
The key difference between cryopreservation and lyophilization is the methods they use. Cryopreservation is a method that involves the rapid freezing of biological materials, while lyophilization is a method that involves removing water through freeze-drying in biological materials.
CONTENTS
1. Overview and Key Difference
2. What is Cryopreservation
3. What is Lyophilization
4. Similarities – Cryopreservation and Lyophilization
5. Cryopreservation vs Lyophilization in Tabular Form
6. Summary –Cryopreservation and Lyophilization
7. FAQ – Cryopreservation and Lyophilization
What is Cryopreservation?
Cryopreservation is a process where biological material such as cells, tissues, or organs are frozen to preserve for a long period of time. In cryopreservation, the biological sample is usually kept at -196 °C using liquid nitrogen. The complete cryopreservation procedure involves steps such as harvesting biological material, adding cryoprotectant material such as glycerol, FBS, salts, sugars, glycol, freezing, storage in liquid nitrogen, and thawing.

Figure 01: Cryopreservation
Some examples of cryopreservation include the cryopreservation of mammalian cell cultures, oocytes, embryos, and sperm. Furthermore, benefits of cryopreservation include fertility treatments, long-distance transportation of biological material, the need for minimal space and labor, safeguarding the genetic integrity of samples, safeguarding germplasm of endangered species, protecting the samples from disease and microbial contamination for long period of time, and preventing genetic drift by cryopreservation of gametes, embryos, etc.
What is Lyophilization?
Lyophilization is also known as freeze drying or cryodesiccation. It is a low temperature dehydration process. This process involves freezing the product and lowering pressure, thereby removing the ice by sublimation. Lyophilization has four major steps: pre-treatment, freezing, primary drying, and secondary drying.

Figure 02: Lyophilization
Examples of lyophilization are high-value freeze-dried products such as seasonal fruits and vegetables and coffee used for military rations, astronauts, or hikers, preserving biological tissues like skin, bone, and cartilage, drug formulation, and diagnostic tests. Furthermore, the benefits of lyophilization may include long shelf life, improved stability, and easy transportation and storage.
Similarities Between Cryopreservation and Lyophilization
- Cryopreservation and lyophilization are methods that are used to preserve delicate biological materials and pharmaceuticals.
- Both use freezing in their procedure.
- Both can be used for tissue preservation.
- They have numerous benefits.
Difference Between Cryopreservation and Lyophilization
Definition
- Cryopreservation is the storage of biological samples at very low temperatures such as -196°C for preservation.
- Lyophilization is the removal of water to preserve perishable materials such as biological materials and pharmaceuticals.
Stages of Procedure
- Harvesting biological material, adding cryoprotectant material, freezing, storing in liquid nitrogen, and thawing.
- Pre-treatment, freezing, primary drying, and secondary drying.
Examples
- Cryopreservation of biological material such as sperm, oocytes, embryos, and cryopreservation of mammalian cell culture.
- Preservation of highly valued food items such as fruits, vegetables, coffee, drug formulation, diagnostic testing, and tissue preservation.
Application
- Cryopreservation is used to preserve biological substances in different sectors, including cryosurgery, molecular biology, ecology, food science, plant physiology, and in many medical applications.
- Lyophilization is used to preserve a wide variety of high-valued foods and beverages, which include fruits, vegetables, soups, juices, baby food, ice cream, snacks, energy bars, ready meals, pet food, and pharmaceuticals.
The following table summarizes the difference between cryopreservation and lyophilization.
Summary – Cryopreservation vs Lyophilization
People have been preserving the biological samples for centuries. Cryopreservation and lyophilization are two preservation techniques that are used to preserve delicate biological materials and pharmaceuticals. Cryopreservation is a preserving technique that uses cooling of biological material to sub-zero temperatures, while lyophilization is a preserving technique in which water is removed from a biological product after it is frozen and placed under a vacuum. This is the key difference between cryopreservation and lyophilization.
FAQ: Cryopreservation and Lyophilization
1. What is cryopreservation in IVF?
- In IVF, cryopreservation is used for freezing eggs, sperm, or embryos to sub-zero temperatures for later use. When the eggs, sperm, or embryos are needed again, they are thawed and fertilized or used in a fertility treatment cycle.
2. What are the benefits of cryopreservation?
- Cryopreservation helps keep biological material stable at cryogenic temperature for a long period of time, preserves the original cell structures, requires minimal space and labor, safeguards the genetic integrity and germ plasma of endangered species, and prevents genetic drift by cryopreserving gametes, embryos, etc., in IVF.
3. What are the disadvantages of cryopreservation?
- Damage to embryos during the freezing process in IVF, embryos that are not viable for freezing, failure to get pregnant after embryos are thawed and implanted and increased frequency of medical issues like preeclampsia and placenta accrete spectrum in pregnancy.
4. Why are drugs lyophilized?
- Lyophilization increases the shelf life of products, and lyophilized drugs are easier to store. It also enhances the stability of dry samples, and there is no need for excessive heating of the product. Moreover, lyophilized drugs are easy to transport safely.
5. What medicines are lyophilized?
- Many of the antibiotics, such as some of the semi-synthetic penicillins, cephalosporins, and some of the salts of erythromycin, doxycycline, and chloramphenicol are manufactured through
Reference:
1. “Cryopreservation.” An Overview | ScienceDirect Topics.
2. “Lyophilization.” Martin Christ Gefriertrocknungsanlagen.
Image Courtesy:
1. “Cryopreservation USDA Gene Bank” By USDA Gene Bank – USDA Gene Bank (CC0) via Commons Wikimedia
2. “Lyophilization of Pharmaceuticals in Vial” By Integrity Bio – Own work (CC BY-SA 3.0) via Commons Wikimedia
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