4 Notes
1. If a passive device is used, a À80
C freezer is required.
2. A À150
C freezer can also be used.
3. All manipulations should be carried out in a well-ventilated
laboratory with sensors to monitor oxygen levels.
4. Delicate or more complex microalgae have a better fitness postthaw when cryopreserved using a controlled rate freezer that
allows for the application of a custom-made cooling ramp,
usually employing faster cooling rates.
5. If you need further information about liquid nitrogen management and safety precautions, how to store your samples safely, or
how to track your cryopreserved samples, you should check the
ISBER Best Practices: Recommendations for Repositories [22].
6. Passive freezers are containers with a lid that hold a deposit for
the cooling solution (pure isopropyl alcohol) and a holder for
the vials (1.8 mL cryovials with a silicon ring for safe closing are
recommended). There are alternatives in the market made of a
thermo-conductive material that does not need alcohol. They
are usually quite affordable methods to cryopreserve the most
resistant microalgae species when there is a À80
C freezer
available.
7. It is important to note that other vials that are stored alongside
the one to be thawed should not be warmed for a prolonged
amount of time as even a small increase in temperature can have
detrimental effects on the cells. To avoid this, the entire container (e.g., cryobox) can be placed into liquid nitrogen while
the vials to be thawed are removed.
Acknowledgments
This work is supported by funding from the INTERREG-IVAtlantic project EBB (European Blue Biobank) and the H2020
INFRAIA project ASSEMBLE-Plus (No. 730984). Authors
would like to acknowledge the staff from ECIMAT Marine Station
(Spain), Roscoff Culture Collection (France), Marine Biological
Association (UK), and the Scottish Association for Marine Science
(UK) for the labor of maintaining the culture collections.
References
1. Friedl T, Day JG, Preisig HR (2004) Culture
collections of algae: increasing accessibility and
exploring algal biodiversity, vol 79. Nova Hedwigia, Berlin, pp 1–327. ISBN 978-3-44302008-8
2. Canavate JP, Lubian LM (1995) The relation
between cooling rates, cryoprotectant concentrations and salinities in the cryopreservation of
marine microalgae. Mar Biol 125:325–334
620
Estefania Paredes et al.
1. If a passive device is used, a À80
C freezer is required.
2. A À150
C freezer can also be used.
3. All manipulations should be carried out in a well-ventilated
laboratory with sensors to monitor oxygen levels.
4. Delicate or more complex microalgae have a better fitness postthaw when cryopreserved using a controlled rate freezer that
allows for the application of a custom-made cooling ramp,
usually employing faster cooling rates.
5. If you need further information about liquid nitrogen management and safety precautions, how to store your samples safely, or
how to track your cryopreserved samples, you should check the
ISBER Best Practices: Recommendations for Repositories [22].
6. Passive freezers are containers with a lid that hold a deposit for
the cooling solution (pure isopropyl alcohol) and a holder for
the vials (1.8 mL cryovials with a silicon ring for safe closing are
recommended). There are alternatives in the market made of a
thermo-conductive material that does not need alcohol. They
are usually quite affordable methods to cryopreserve the most
resistant microalgae species when there is a À80
C freezer
available.
7. It is important to note that other vials that are stored alongside
the one to be thawed should not be warmed for a prolonged
amount of time as even a small increase in temperature can have
detrimental effects on the cells. To avoid this, the entire container (e.g., cryobox) can be placed into liquid nitrogen while
the vials to be thawed are removed.
Acknowledgments
This work is supported by funding from the INTERREG-IVAtlantic project EBB (European Blue Biobank) and the H2020
INFRAIA project ASSEMBLE-Plus (No. 730984). Authors
would like to acknowledge the staff from ECIMAT Marine Station
(Spain), Roscoff Culture Collection (France), Marine Biological
Association (UK), and the Scottish Association for Marine Science
(UK) for the labor of maintaining the culture collections.
References
1. Friedl T, Day JG, Preisig HR (2004) Culture
collections of algae: increasing accessibility and
exploring algal biodiversity, vol 79. Nova Hedwigia, Berlin, pp 1–327. ISBN 978-3-44302008-8
2. Canavate JP, Lubian LM (1995) The relation
between cooling rates, cryoprotectant concentrations and salinities in the cryopreservation of
marine microalgae. Mar Biol 125:325–334
620
Estefania Paredes et al.