Cell freezing

Choosing the right cell freezing method


coolcell cell freezing
The current recommendation for freezing stem cells, primary cells, PBMCs and cell lines is that they be cooled gradually to approximately -80°C at a controlled rate of -1°C per minute. This can be achieved using CoolCell® alcohol-free cell freezing container in conjunction with a -80°C freezer. 


Learn how with this short video.


 Fig 1.  CoolCell performance compared to a controlled-rate freezer

Multiple leukapheresis-like products were processed into PBMCs and frozen using either a CoolCell or controlled-rate freezer (CRF).  In both cases, cells were frozen at approximately 108 cells per mL in CryoStor® CS10.  Vials were stored in liquid nitrogen for approximately 2-3 weeks and thawed the same day using a water bath.  The CoolCell and CRF methods were comparable in both recovery and viability. (Data generated by UCSF Division of Transplant Surgery)




TxCell, SA (Valbonne, France).  In a feasibility study for their Ovasave® clinical trials, France-based TxCell, SA determined CoolCell cell freezing containers performed equivalent to a controlled-rate freezer (CRF) for the development of of their cell therapy products. (Figure 2).  Because CoolCell is considerably easier to deploy to clinical sites, is more cost-effective and requires no maintenance, it was adopted over a CRF for the Ovasave phase 2b trial.  (Please visit our Cell Therapy Processes page for more information on the TxCell study.)  Learn how TxCell qualified and adopted CoolCell for their Treg clinical trial.

coolcell equivalent to crf treg


Fig 2.  CoolCell performance compared to a controlled-rate freezer 
Performance test: Effects of freezing on antigen-specific Treg (Ag-Treg) cell therapy products; Ag-Tregs (n = 6) were frozen at a concentration of 1 to 10 × 106 cells/mL using the CoolCell freezing device or programmable freezer (freezing rate of –1 °C/min). Viability and absolute viable cell count of thawed Ag-Treg cell therapy products were evaluated by flow cytometry.  (Data generated by TxCell, SA)






CoolCell outperforms other passive freezing methods


An independent study conducted by Roslin Cellab, showed a 33 percent increase in hESC viable cell count using a CoolCell container (P<0.005) when compared to other passive freezing methods three days post-thaw (Figure 3).

coolcell hESC performance

Fig 3.  CoolCell performance compared to a controlled-rate freezer
Post-thaw viability of Human Embryonic Stem Cells (RC-10): Human embryonic stem cells, RC-10, grown to confluence were harvested and suspended in a cryopreservative at 2 x 106 cells/vials and then frozen in 1.0 ml cryogenic vials using the methods above.  After at least two weeks in LN2, 3 vials from each treatment were thawed and cells were counted immediately (Day 1) or after three days growth (Day 3). The CoolCell freezing method led to a slight increase in the number of viable cells on day 1 and a 33% increase in the number of cells after 3 days of growth. (Data provided by Roslin Cellab, Scotland)


See more CoolCell data.


How do CoolCell cell freezing containers compare to other freezing methods?

coolcell, cryopreservation

CoolCell container

• Consistent -1˚C/minute freeze rate to all vials
• Alcohol-free; no ongoing cost, maintenance or waste
• Reproducible freezing profiles
• Easily deployable to multiple sites
• 5-10 minute wait period between freeze runs (allows 2 freeze runs per day)

isopropanol container

Isopropanol-based container

• Stated freeze rate of -1°C/minute, but varies based on vial position
• Continuous isopropanol replenishment, cost and waste
• Isopropanol is a variable in each freeze run hindering consistent reproducibility
• Long wait periods between freeze runs

controlled-rate freezer

Controlled-rate freezer

• Expensive
• Difficult to maintain
• Not easily deployable to multiple sites




How do CoolCell containers work?


CoolCell freezing containers are passive devices that provide a controlled -1℃/minute freeze rate to all cryogenic vials when placed in a -80℃ freezer. CoolCell containers do not require isopropanol or any fluids to regulate heat removal and provide uniform and reproducible freezing to all vials. (Figure 4) See more information here.

cryopreservation, coolcell

  • • Highly insulative cross-linked closed-cell polyethylene foam has superior material properties at cryogenic temperatures

  • • Radially-symmetric vial distribution ensures identical heat removal profiles for each vial

  • • Solid alloy thermal core fine-tunes and balances the freezing profile

  • • Extremely durable single-block base construction provides nearly indefinite product life-cycle without change in performance

Fig 4.  Freezing consistency using a CoolCell® container.
 Five consecutive freeze runs in a -80℃ freezer show highly reproducible freezing profiles.


Choose the right CoolCell cell freezing container for your application





More Customer Reviews


"CoolCell performs similarly to a controlled-rate freezer with regard to viability and recovery when freezing leukapheresis-like starting material at high concentrations in CryoStor CS10.  CoolCell is less expensive than a controlled-rate freezer, does not contain liquid, can be acclimated quickly for fast turn-around, and is transportable." 
- Amy Putnam, leading a Treg manufacturing team that supports clinical trials in autoimmunity and transplantation, UCSF Diabetes Center and Transplant Surgery
"The device is elegant in its simplicity and ease of use and offers researchers a method to cryopreserve cells in a standardized fashion with great reproducibility and little variability in performance."
- Kevin Grady, ATCC


"We run a registry in which large amounts of PBMCs are processed for long-term cryopreservation. After testing
the CoolCell, we found slightly better cell viability (>90%) than our current cell freezing containers, and there is
no isopropanol waste generated.  Overall, the CoolCell has proven to set a new bar in cryopreservation."
- Rohit Gupta, Stanford University  


"We have been using a cell freezing system which requires 100% isopropyl for the stepwise (1°C/min) cooling of cell lines for cryopreservation.  This required the regular and frequent changes of the isopropyl alcohol to maintain the unit's performance, due to evaporation and changes in concentration of the isopropyl alcohol.  As soon as we used 
the BioCision CoolCell, its ease of use and the low (zero) maintainence of the unit were quickly apparent to us.   
This is by far and away the best bench top technology to enter the field of cell cryopreservation for decades."

- John Gardner, Roslin Cellab Project Leader, Scotland 


The BioCision cell freezing products described above are for laboratory research use only. Any intended use for diagnostic purposes, direct transfusion, or in the production of therapeutic product(s) or vaccines(s) may require advance regulatory clearance which is the sole responsibility of the user, as this is not a medical device that has undergone medical device registration, clearance, or approval by the U.S. Food and Drug Administration (FDA), European Union, Health Canada, or the Australian Therapeutic Goods Administration. Research Only Device: Limited by Federal Law (United States) to Research Use Only.


Standardized Cryopreservation of Pluripotent Stem Cells

Rick I. Cohen, Maria L. Thompson,Brian Schryver, Rolf O. Ehrhardt
Rutgers University, Piscataway, New Jersey, BioCision LLC, Larkspur, California
Curr. Protoc. Stem Cell Biol. 28:1C.14.1-1C.14.10.



Standardized Cryopreservation of Human Primary Cells

Thomas V. Ramos, Aby J. Mathew, Maria L. Thompson, Rolf O. Ehrhardt HemaCare Corporation, Van Nuys, California,  BioLife Solutions, Bothell, Washington, BioCision, Larkspur, California


Cryopreservation and Thawing of Cells

Yokoyama WM, Thompson ML, Ehrhardt RO.
University of California School of Medicine, San Francisco, CA
Curr Protoc Immunol. 2012 Nov;99 Appendix 3:3G