PT  - JOURNAL ARTICLE
AU  - Keiran Stevenson
AU  - Alexander F. McVey
AU  - Ivan B.N. Clark
AU  - Peter S. Swain
AU  - Teuta Pilizota
TI  - General calibration of microbial growth in microplate readers
AID  - 10.1101/061861
DP  - 2016 Jan 01
TA  - bioRxiv
PG  - 061861
4099  - http://biorxiv.org/content/early/2016/07/04/061861.short
4100  - http://biorxiv.org/content/early/2016/07/04/061861.full
AB  - Optical density (OD) measurements of microbial growth are one of the most common techniques used in microbiology, with applications ranging from antibiotic efficacy studies, studies of growth under different nutritional or stress environments, to studies 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.