Some researchers have applied immobilization technologies to the stock culture management as an alternative to the common cryopreservation processes, since entrapment processes are cheaper and easier (Chen 2001; Faafeng et al. 1994; Hertzberg and Jensen 1989). Immobilization can also provide protection of the cells toward being consumed by any zooplankton present in the same aquatic ecosystems.

Chen (2001) observed that the immobilized Scenedesmus quadricauda cells in alginate beads can preserve their physiological activities for a long time, even after three years of storage in darkness at 4 °C. This observation was explained by the entrapped cells self-consuming their own pyrenoid reserves. Transmission electron microscopic images of immobilized S. quadricauda cells showed that they lose their pyrenoids after extended storage, which is then rebuilt when the cultures are placed back into their nutrient media under light conditions.

Lebeau et al. (1998) also established the ability to store marine diatom H. ostrearia cells for nearly 2 months after their entrapment in calcium alginate beads and later used them as a substrate source for the greening of oysters. As a follow-up study, the same group achieved a longer term storage when H. ostrearia diatom cells were entrapped in alginate beads and kept at 4 °C (Gaudin et al. 2006). Chen (2003) stored Isochrysis galbana marine microalgal cells for more than a year after immobilizing them in alginate at 4 °C in dark conditions, and the cells were then used for feeding clam cultures.