February 16, 2024

Study: Optimizing Cell Viability During CHO Cell Freezing

Improving Cryogenic Freezing of a Mammalian Cell Line

A study was conducted aiming to optimize the cryogenic freezing process of CHO-K1 cell line using an innovative controlled rate liquid nitrogen freezer (RoSS.LN2F). The mammalian cells were filled into 250mL single-use bags and protected by RoSS.KSET.

The study included three different freeze runs at different cooling rates in the controlled rate RoSS.LN2F, as well as an additional uncontrolled freeze run in a static freezer for comparison purposes.  

To comprehensively assess the impact of varying freezing rates on post-thaw cell recovery, the study incorporated three viability assays: Trypan blue, LIVE/DEAD and Fluorescence.

Study Results: Optimal Freezing Protocol for Cell-based Therapies

Intra-experimental variations between the different freezing runs were minor. The study suggests that a freezing rate of −1°C/min is optimal for mammalian cell lines.

However, the study also emphasized on cell survival rate for other freezing rates, as the optimal cooling rate is not limited to -1°C/min. The results show that the range of optimal cooling rates can be expanded to a certain level.

The study also highlights the importance of controlling the freezing process. What are the consequences of freezing in an uncontrolled environment, such as a static freezer, compared to a recipe-driven, standardized, and scalable controlled freezing protocol?  

Please download the Study Summary for further information.

Download Study Summary: Optimizing the freezing protocol for CHO-K1 cells in RoSS.LN2F

Learn study results from a joint study between Single Use Support and the Management Center Innsbruck, where freezing protocols were tested to find the optimal freezing rate for CHO-K1 cells. 

Study Summary_Optimization of the freezing protocol for CHO-K1 cells

Study: Increased CHO Cell Viability with Controlled Liquid Nitrogen Freezer

Filesize: 0.7 MB – Mime-Type: application/pdf

More Information

RoSS.KSET top view

ROSS.KSET | Protecting small single-use bags

RoSS.KSET offers the protection for drug substances with volumes less than 250 mL. The shell of our CGT bag protection system is robust, closed, safe and sterile – most suitable for cell and gene therapies or clinical studies.

For larger volumes, RoSS can protect one or multiple single-use bags in one shell.

Cryogenic Freezer RoSS LN2F

RoSS.LN2F | Cryogenic Freezer

RoSS.LN2F is a powerful cryogenic controlled rate freezer for temperatures down to -170°C/-274°F. An enclosed LN2 system and our innovative direct injection system ensure no direct exposure and no mechanical compressors are needed. This ensures a safe, low-maintenance and energy-saving handling.

How to measure and improve cell viability?

How to measure and improve cell viability?

Cell viability is a fundamental parameter in cell-based biopharma processing and cell banking. Therefore, it is essential not only to measure cell viability, but also to take measures for its improvement. Learn more in this article.

Cell viability: 7 facts to be aware of

Cell viability: 7 facts to be aware of

In research, medicine and biotechnology, cell viability is an elementary parameter and Critical Quality Attribute (CQA). In this article, we will present you 7 facts regarding the term, related concepts, improvement possibilities and more.

Freezing Mammalian Cell Line for increased CHO cell viability

Alexander Fuchs

Head of Product Line Management

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