title: The use of physical and virtual infrastructures for the validation of algal cryopreservation methods in international culture collections.
abstract: Two cryopreservation methods, colligative cryoprotection coupled with controlled cooling and vitrification-based, encapsulation-dehydration were validated by five members of the EU research infrastructure consortium, COBRA, and two independent external validators. The test strain Chlorella vulgaris SAG 211-11b was successfully cryopreserved using two-step cooling employing passive (Mr Frosty) and Controlled Rate Freezers (CRF) attaining the desired recovery target within 15% of the median viability level (94%). Significant differences (p < 0.05) between cooling regimes were observed where Mr Frosty was more variable (Inter-Quartile Range being 21.5%, versus 13.0% for CRF samples). Viability assessment using fluorescein diacetate gave significantly (P < 0.0001) higher survival than growth in agar with median values being 96% and 89%, respectively. On employing encapsulation-dehydration, greater variability between some validators was observed, with six labs observing recovery in 100% of the beads (84-95% of cells surviving) and one lab observing survival in 80% of the treated beads. Bead disruption followed by algal growth in agar was considered the most reliable and accurate method of assessing cell survival for encapsulation-dehydration.
authors: Scottish Association for Marine Science, Dunbeg, Argyll, UK.
authors: John G
authors: JG
authors: Day
authors: Maike
authors: M
authors: Iorenz
authors: Thomas A
authors: TA
authors: Wilding
authors: Thomas
authors: T
authors: Friedl
authors: Keith
authors: K
authors: Harding
authors: Thomas
authors: T
authors: Pröschold
authors: Debra
authors: D
authors: Brennan
authors: Julia
authors: J
authors: Müller
authors: Lília M A
authors: LM
authors: Santos
authors: M Fátima
authors: MF
authors: Santos
authors: Hugo C
authors: HC
authors: Osório
authors: Raquel
authors: R
authors: Amaral
authors: Alena
authors: A
authors: Lukesova
authors: Pavel
authors: P
authors: Hrouzek
authors: Martin
authors: M
authors: Lukes
authors: Josef
authors: J
authors: Elster
authors: Jaromír
authors: J
authors: Lukavsky
authors: Ian
authors: I
authors: Probert
authors: Matthew J
authors: MJ
authors: Ryan
authors: Erica E
authors: EE
authors: Benson
mesh_terms: D002470:Cell Survival; D002478:Cells, Cultured / Q000166:cytology*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D056890:Eukaryota / Q000166:cytology*; D066298:In Vitro Techniques
chemical_list: D003451:Cryoprotective Agents