Nat. Biotechnol. 30, 578–580 (2012); doi:10.1038/nbt.2295; published online 9 July 2012; corrected after print 7 December 2012

In the version of this article originally published, On-Q-Ity platform was called by its previous and outdated name, C5 (Circulating Cancer and Characterization Chip). It should have been called OnQChip. The error has been corrected in the HMTL and PDF versions of the article.