title: General calibration of microbial growth in microplate readers.
abstract: Optical density (OD) measurements of microbial growth are one of the most common techniques used in microbiology, with applications ranging from studies of antibiotic efficacy to investigations of growth under different nutritional or stress environments, to characterization of different mutant strains, including those harbouring synthetic circuits. OD measurements are performed under the assumption that the OD value obtained is proportional to the cell number, i.e. the concentration of the sample. However, the assumption holds true in a limited range of conditions, and calibration techniques that determine that range are currently missing. Here we present a set of calibration procedures and considerations that are necessary to successfully estimate the cell concentration from OD measurements.
authors.affiliation: Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, Edinburgh, EH9 3FF, United Kingdom.
authors.forename: Keiran
authors.initials: K
authors.lastname: Stevenson
authors.affiliation: Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, Edinburgh, EH9 3FF, United Kingdom.
authors.forename: Alexander F
authors.initials: AF
authors.lastname: McVey
authors.affiliation: Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, CH Waddington Building, Mayfield Road, Edinburgh EH9 3JD, UK.
authors.forename: Ivan B N
authors.initials: IBN
authors.lastname: Clark
authors.affiliation: Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, CH Waddington Building, Mayfield Road, Edinburgh EH9 3JD, UK.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Swain
authors.affiliation: Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, Edinburgh, EH9 3FF, United Kingdom.
authors.forename: Teuta
authors.initials: T
authors.lastname: Pilizota
mesh_terms: D002138:Calibration; D015169:Colony Count, Microbial / Q000295:instrumentation / Q000379:methods; D004926:Escherichia coli / Q000254:growth & development*; D009391:Nephelometry and Turbidimetry; D015203:Reproducibility of Results