Correction to: Nature Protocols https://doi.org/10.1038/s41596-018-0097-3, published online 9 January 2019

During the production process, the authors of this paper supplied revised versions of Figs. 2–5, Supplementary Tables 1–4, and Supplementary Videos 1–3, but because of publisher error, these revised items were not included in the final published version of the protocol. The figures have been updated in the PDF and HTML versions of the paper, and the revised Supplementary Information files are now available online. We note that the figures have been revised to improve their resolution only; the content of the figures and the data reflected remain unchanged. Also, print requirements impose some limits on figure resolution, but the authors have made very high-resolution versions of Figs. 2–5 available as Source data.