Cell Preservation

There are two common methods of cell preservation at low temperature: hypothermic preservation at tem­peratures above freezing and cryogenic preservation at temperatures below freezing. Hypothermic preser­vation allows short term storage of tissues and organs prior to further investigation. Cryogenic preservation is used for the establishment of cell banks to ensure reproducible results in research by stabilizing living cells. Using cryopreservation media the cells are pro­tected from damage which can occur during freezing and warming processes. The most commonly used cryoprotective agents serve several functions during the freezing process, e.g. freezing point depression, protection of solution effects and extra- and intracel­lular ice crystal formation, but are often toxic in high concentration.

Therefore cryopreservation media must fulfil the follo­wing requirements:

• Increased long-term storage
• Suppression of ice crystal formation
• Cryoprotective additives with improved formulations
• Highest viability after thawing

Cell Banking

Cryopreservation of cells plays an important role in establishing cell stocks. Cryopreserved cells assure an adequate supply in case of microbial contamination of currently used cells. By the implementation of a Master Cell Bank (MCB) and Working Cell Bank (WCB) all potential risk factors may be minimized. Establishing a MCB and a WCB are the first steps in the manuf­acturing process for biopharmaceuticals and can be prepared under serum free conditions with defined and animal derived component free cryopreservation media.

In the case of using cryopreservation media with serum, we strongly recommend the usage of foetal bovine serum from Australia for highest virus safety.

Cold storage of Tissues and Organs

For short term preservation tissues and organs can be stored under hypothermic conditions in the presence of specific media components which prevent the cell decay by reduction of free oxygen radicals and inhibi­tion of different proteases and nuclease. The cold sto­rage of tissues and organs with optimized hypothermic preservation media is a prerequisite for successful animal organ transplantation.

Several commercial hypothermic preservation media are available such as the UW-, Celsior- and HTK- soluti­on. They are based on saccharides and derivates, salts, energy sources, reducing agents and other stabilizers.

PAA's new Product Line for Cell Preservation

PAA has developed a family of new cyropreservation solutions that include new crystal suppressing agents.

Based on successfully developed hypothermic solutions for cold storage of organs PAA offers with CryoMaxx I and CryoMaxx II serum free cryopreservation media with different concentrations of DMSO for highest cell viability after thawing. Furthermore CryoMaxx SF, a serum free medium based on methylcellulose is available.

For classical cryopreservation of cells the serum con­taining medium CryoMaxx S with highest viability can be supplied.

Tissues and organs can be effectively preserved under cold storage with PAA’s new preservation medium CoolStar based on the well-known UW-, Celsior- and HTK- solutions. Our new formulation reduces oxidative damage and degradation by proteases and nucleases more efficiently. Tissues and organs are success­fully prepared for transplantation experiments.