Nat. Protoc. 9, 2237–2255 (2014); doi:10.1038/nprot.2014.150; published online 28 August 2014; corrected after print 12 September 2014

In the version of this article initially published, one of the two affiliations of one of the authors (Michael Kassiou) was incorrect. The mistaken affiliation read: “6Faculty of Health Sciences, Macquarie University, Sydney, New South Wales, Australia.” The correct affiliation is: “6Faculty of Health Sciences, University of Sydney, Sydney, New South Wales, Australia.” The error has been corrected in the HTML and PDF versions of the article.