Detection of 2-Alkyl-4-Quinolones Using Biosensors

  • Stephen P. DiggleEmail author
  • Matthew P. Fletcher
  • Miguel Cámara
  • Paul Williams
Part of the Methods in Molecular Biology book series (MIMB, volume 692)


2-Alkyl-4-quinolones (AQs) such as 2-heptyl-3-hydroxy-4-quinolone (PQS) and 2-heptyl-4-quinolone (HHQ) are quorum sensing signal molecules. Here we describe two methods for AQ detection and quantification that employ thin layer chromatography (TLC) and microtitre plate assays in combination with a lux-based Pseudomonas aeruginosa AQ biosensor strain. For TLC detection, organic solvent extracts of bacterial cells or spent culture supernatants are chromatographed on TLC plates, which are then dried and overlaid with the AQ biosensor. After detection by the bioreporter, AQs appear as both luminescent and green (pyocyanin) spots. For the microtitre assay, either spent bacterial culture supernatants or extracts are added to a growth medium containing the AQ biosensor. Light output by the bioreporter is proportional to the AQ content of the sample. The assays described are simple to perform, do not require sophisticated instrumentation, and are highly amenable to screening large numbers of bacterial samples.

Key words

Pseudomonas aeruginosa Biosensor 2-Alkyl-4-quinolones 2-Heptyl-3-hydroxy-4-quinolone 2-Heptyl-4-quinolone pqsA 



We gratefully acknowledge the Royal Society (SPD) and BBSRC (MPF) for funding.


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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Stephen P. Diggle
    • 1
    Email author
  • Matthew P. Fletcher
    • 1
  • Miguel Cámara
    • 2
  • Paul Williams
    • 2
  1. 1.School of Molecular Medical Sciences, Centre for Biomolecular SciencesUniversity of NottinghamNottinghamUK
  2. 2.Centre for Biomolecular Sciences, School of Molecular Medical SciencesUniversity of NottinghamNottinghamUK

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