Controlled ATMP freezing: the role of cooling rate and phase transition control in cell viability

Cryopreservation of ATMPs requires precise control of the freezing process to maintain cell viability. This article presents a study conducted by Single Use Support GmbH in collaboration with Management Center Innsbruck examining the effect of different controlled cooling rates (−0.68, −1.15, and −4.28 °C/min) on Chinese Hamster Ovary (CHO)-K1 cell viability, alongside an uncontrolled freezing comparator. Results demonstrated that controlled freezing at approximately −1 °C/min achieved the highest viability (~95% by live/dead assay), and that phase transition control is a critical determinant of cell survival, independent of cooling rate. The study also highlights the role of user‑defined, recipe‑driven freezing systems in implementing controlled cryopreservation workflows within GMP manufacturing environments.

What you will learn

01

Why the −1 °C/min benchmark only holds within controlled-rate systems with active phase transition management – not in static freezers that happen to reach the same rate

02

How phase transition control reduces variability ~14-fold vs static freezing (CV 2.3% vs 32.6%), and why this interval is the period of greatest osmotic and mechanical stress on cells

03

How plate-based and cryogenic LN2 freezing systems with user-defined recipes deliver reproducible, high-viability cryopreservation and reduce cryoconcentration in GMP workflows

Key interests

Cryopreservation

ATMP Manufacturing

Controlled-Rate Freezing

Phase Transition Control

Cell Viability

CHO-K1 Cells

GMP Compliance

Cold-Chain Management