Real-Time Digital Bright Field Technology for Rapid Antibiotic Susceptibility Testing

  • Chiara CanaliEmail author
  • Erik Spillum
  • Martin Valvik
  • Niels Agersnap
  • Tom Olesen
Part of the Methods in Molecular Biology book series (MIMB, volume 1736)


Optical scanning through bacterial samples and image-based analysis may provide a robust method for bacterial identification, fast estimation of growth rates and their modulation due to the presence of antimicrobial agents. Here, we describe an automated digital, time-lapse, bright field imaging system (oCelloScope, BioSense Solutions ApS, Farum, Denmark) for rapid and higher throughput antibiotic susceptibility testing (AST) of up to 96 bacteria–antibiotic combinations at a time. The imaging system consists of a digital camera, an illumination unit and a lens where the optical axis is tilted 6.25° relative to the horizontal plane of the stage. Such tilting grants more freedom of operation at both high and low concentrations of microorganisms. When considering a bacterial suspension in a microwell, the oCelloScope acquires a sequence of 6.25°-tilted images to form an image Z-stack. The stack contains the best-focus image, as well as the adjacent out-of-focus images (which contain progressively more out-of-focus bacteria, the further the distance from the best-focus position). The acquisition process is repeated over time, so that the time-lapse sequence of best-focus images is used to generate a video. The setting of the experiment, image analysis and generation of time-lapse videos can be performed through a dedicated software (UniExplorer, BioSense Solutions ApS). The acquired images can be processed for online and offline quantification of several morphological parameters, microbial growth, and inhibition over time.

Key words

Automated digital time-lapse bright field screening system oCelloScope Qualitative and quantitative image-based analysis Generation of time-lapse videos UniExplorer Bacterial cultures and clinical isolates Antibiotic resistance testing 


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Copyright information

© Springer Science+Business Media, LLC 2018

Authors and Affiliations

  • Chiara Canali
    • 1
    Email author
  • Erik Spillum
    • 1
    • 2
  • Martin Valvik
    • 1
  • Niels Agersnap
    • 1
  • Tom Olesen
    • 1
    • 2
  1. 1.Philips BioCell A/SAllerødDenmark
  2. 2.BioSense Solutions ApSFarumDenmark

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