Evaluation of a lens-free imager to facilitate tuberculosis diagnostics in MODS

Leonardo Solis, Jorge Coronel, Daniel Rueda, Robert H. Gilman, Patricia Sheen, Mirko Zimic

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Summary Tuberculosis (TB) control efforts are hampered by a mismatch in diagnostic technology. Lack of adequate early diagnostics and Multi-drug resistant (MDR) detection is a critical problem in control efforts. Alternate and novel diagnostic approaches are required, especially in low-resources settings where they are needed most. The Microscopic Observation Drug Susceptibility (MODS) assay is a cost-effective, highly sensitive, and specific method based on the detection of characteristic cording growth patterns of Mycobacterium tuberculosis (MTB), in microscopic examination of a liquid culture under an inverted microscope. By adding antimicrobials to the wells, MODS also determines antimicrobial susceptibility in both MDR and Extreme Drug Resistant (XDR) tuberculosis. The interpretation of a MODS culture performed in a 24 well plate, requires an extensive inspection over the entire surface to detect TB cords. This process requires significant time and effort from a trained microscopist. We evaluated a lens-free imager system, able to render microscopic images of live specimens, for the proof of principle to be used for MODS culture interpretation. The lens-free imager system is able to digitalize a 24-mm 2 surface with approximately 40X magnification in a single capture. The evaluation of the lens-free imager found that it produced microscopic images that were adequate for MODS interpretation by a human expert. Compared to the average time that takes a microscopist to completely examine a MODS culture sample, the lens free imager notably reduced the time of inspection. Therefore, lens-free imager variants may constitute promising systems to aid in the diagnostics of tuberculosis, by simplifying and reducing the time of inspection and permitting automatization of MODS interpretation.

Original languageEnglish (US)
Pages (from-to)26-32
Number of pages7
StatePublished - Mar 2016


  • Diagnostics
  • Lens-free imager
  • Lens-free microscopy
  • MDR
  • MODS
  • Microscopy
  • Multi drug resistance
  • Tuberculosis
  • ePetri

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Microbiology (medical)
  • Infectious Diseases


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