Nat. Biotechnol. 24, 708–712 (2006); published online 21 May 2006; corrected after print 25 July 2006

In the Methods section, p.711, “Library construction and selection,” line 11 of the print version of this article and the version initially published online, the plates used for rounds of ON selection were incorrectly said to contain 3OC6HSL. The text should read “...plated onto LB agar plates containing 50 μg/ml kanamycin, 150 μg/ml chloramphenicol and 100 nM C10HSL.” The error has been corrected in the HTML and PDF versions of the article.