Scientific Reports 5: Article number: 9583; published online: 31 March 2015; updated: 08 March 2016

This Article contains an error in the Methods section under subheading ‘Freeze substitution, resin embedding and sectioning’.

“The first 12 h of polymerization were done at −45 °C, during which the samples were covered with foil and indirectly exposed to UV light. The cover was then removed and samples were warmed to 0 °C at 5 °C/h and polymerized for a further 8 h, then left in the fumehood at room temperature for 1–2 days.”

should read:

“The first 12 h of polymerization were done at −45 °C, during which the top of the samples were covered with foil and indirectly exposed to UV light. The cover was then removed and samples were polymerized for a further 12 h at −45 °C, then warmed to 0 °C over a 12 h period and polymerized at 0 °C for a further 12 h. Samples were then left in the fume hood at room temperature for 1–2 days.”