Last Updated on December 29, 2023

In this article, Mr. Shinji Azuma, representing Strex, has been interviewed in a Q&A format to explain the overview, benefits, and applications of the Program Freezer.

The Programmable Freezer & CytoSAVER Programmable Freezer FZ Series: An Introduction

Rapidly freezing cells can lead to ice crystal formation within the cell body. As a result, the cells can burst because ice occupies more volume than liquid. Therefore, the slow freezing method is the preferred for most cell types.

There are two methods to perform slow freezing:
The first involves placing cells in a container with alcohol and placing them in a freezer. However, the freezing rate is unknown with this method, and we cannot log data, amongst other issues. The second method allows for accurately controlling the cooling process using the Controlled Rate Freezer, which solves the aforementioned issues.

With Controlled Rate Freezers or Programmable Freezers, you can achieve precise control over the freezing process, overcoming challenges like unknown cooling curves and the inability to log data associated with the method involving alcohol and a freezer.

Most Programmable Freezers traditionally use liquid nitrogen and electricity to cool cells. Due to the use of liquid nitrogen, these devices are typically large, standalone units, roughly the size of a desk.

Strex has manufactured the Programmable Freezer series, CytoSAVER FZ, to operate exclusively on electricity for cooling. It also features a built-in computer to eliminate the need for manual login and logout procedures. Additionally, the device supports external communication to allow for monitoring from locations beyond the clean room environment.

The main benefit of the CytoSAVER is that it is liquid nitrogen free. This feature allows for the freezer to be more compact and mitigates concerns about mycoplasma contamination, particularly in clean rooms.


CytoSAVER Programmable Freezer FZ series

There are various products within the Programmable Freezer category. What makes the FZ Series stand out from these products?

The FZ Series provides a more cost-effective solution than many foreign products. Additionally, having local support staff allows for swift assistance in case of any issues. Numerous companies and research laboratories have widely adopted the FZ series, accumulating real-world use cases. The user-friendly touch panel and neatly generated cooling logs enhance usability in research labs. The FZ series’ attractiveness lies in its immediate usability upon installation in a laboratory setting.

LCD Touch Panel


After each execution, cell freezing treatment data results are generated in PDF format.

What disadvantages are there to consider?

Firstly, an initial investment is necessary when compared to cooling containers. However, since cooling containers can be bulky, Programmable Freezers may offer more advantages from a long-term cost perspective.

Additionally, while it may be a less common scenario, it’s worth noting that in cases requiring rapid freezing or rapid cell freezing, methods using liquid nitrogen may be more suitable than the Programmable Freezer, which offers stronger freezing capabilities.

Please explain the differences between the product models with each model number.

The CytoSAVER Programmable Freezer FZ series has four models: FZ-2100/2200/3100/3200. The FZ-2200 and FZ-3200 models comply with FDA Title 21 CFR Part 11 (cGMP). FZ-2100 and FZ-2200 can accommodate up to 81 samples of 1 mL each, while FZ-3100 and FZ-3200 are models that can handle 171 samples of 1 mL each. They also support blood bags by removing the blocks.

It can accommodate up to 81 samples of 1 mL each.
Supports blood bags by removing the blocks.

Similar to FZ-2100 but with additional features.
Complies with FDA Title 21 CFR Part 11 (cGMP).
It can handle up to 81 samples of 1 mL each.
Supports blood bags by removing the blocks.

It can accommodate up to 171 samples of 1 mL each.
Supports blood bags by removing the blocks.

Similar to FZ-3100 but with additional features.
Complies with FDA Title 21 CFR Part 11 (cGMP).
It can handle up to 171 samples of 1 mL each.
Supports blood bags by removing the blocks.

What common application examples and cell types does the Programmable Freezer support?

The most prevalent application examples are stem cells, including induced pluripotent stem cells or iPS cells. There are also numerous instances of usage for differentiated neural cells. Usage is increasing for blood cells, cardiac muscle cells, and umbilical cord blood.

Who are the common users of the Programmable Freezer, and what types of institutions have adopted it?

Numerous universities, research institutions, and companies have widely adopted programmable Freezers. It is utilized by a diverse range of users, including companies and universities conducting stem cell research and those handling umbilical cord blood and tissue.

What can be anticipated regarding future developments, and what additional details can you provide?

The CytoSAVER Programmable Freezer FZ series is versatile and suitable for companies and laboratories engaged in cell research and users dealing with blood and antibodies. We remain committed to delivering high-performance and high-quality Programmable Freezers in the future.

To learn more about the CytoSAVER contact us anytime for an online demo.