Mushroom coral larvae have come back to life after being frozen and then thawed, researchers reported October 24 in Scientific Reports. The successful larvae revival is a small step toward helping conservationists save at-risk coral species and boost the biodiversity of coral reefs worldwide.
When thawing frozen cells, researchers have to work quickly to prevent ice crystals from forming and rupturing the cell membrane. In the study, researchers encapsulated coral larvae in cryoprotectant and gold nanorods, then fired an infrared laser pulse at them. The gold nanorods absorbed the laser pulse and converted it into heat, which then spread uniformly through the larvae, while the cryoprotectant warded off any ice crystal formation.
While the numbers of larvae revived in this study were small, the researchers hope to scale-up the thawing process so they can reanimate hundreds of thousands of larvae at a time in the future for repopulating reefs.
J. Daly et al. “Successful cryopreservation of coral larvae using vitrification and laser warming,” Scientific Reports, doi:10.1038/s41598-018-34035-0, 2018.