Cryopreservation of primary cultures of mammalian somatic cells in 96-well plates benefits from control of ice nucleation

Cryopreservation as a Key Element in the Successful Delivery of Cell-Based Therapies—A Review

“… The effect of sample volume on spontaneous ice nucleation in a typical cell suspending medium. Drawn using internal data as well as data from Daily et al ( 165 ). …”

“…Fortuitously, spontaneous ice nucleation for these volumes will occur at a temperature significantly closer to the melting point than would be the case for smaller volumes ( Figure 4 ). Consequently, a limited, damaging effect is achieved without further intervention ( 165 ), although practical studies investigating the impact of induced nucleation for these larger sample volumes are lacking.…”

On-chip density-based sorting of supercooled droplets and frozen droplets in continuous flow

“…This technique could aid in a number of applications as outlined in the introduction. In particular, we can see immediate potential for use in two fields, namely low temperature biology 9 and atmospheric ice nucleation. 2,3 In the former case, it could be envisaged that water droplets containing cells could be exposed to "ideal" freezing conditions (e.g.…”

“…This might be a useful method for reducing aliquot-to-aliquot variability in viability related to freezing temperature. 1,9 While this approach is unlikely to be cost-effective for cells in plentiful supply, it might be useful for high-value cells such as human stem cells, which have potential for use in cancer treatments. 75 A particularly useful application could be in the selection and concentration of biological ice-nucleating materials that exhibit exceptional ice-nucleating abilities at warmer temperatures, such as certain strains of bacteria, which would enable the subsequent culturing of a highly active form of ice nucleators.…”

“…Some cryopreservation strategies avoid ice formation by cooling and vitrifying the samples, whereas others involve minimising the extent of supercooling by nucleating ice at as high a temperature as possible by inducing ice nucleation under controlled conditions. 1,8,9 If some aliquots freeze or vitrify in an optimal manner while others do not, this could result in a mixture of samples containing cells or tissues of varying viability. In principle, if the samples that have undergone controlled ice nucleation could be selected and only those aliquots expected to contain viable biological matter stored, the quality and reproducibility of the cryopreserved samples would be improved.…”