Byron Brehm-Stecher - Enhanced dark field microscopy for rapid artifact-free detection of nanoparticle binding to Candida albicans cells and hyphae.

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      Publication Details (including relevant citation   information):

      Biotechnol J. 2009 Jun;4(6):871-9.

      Abstract:

      We surveyed a panel of 13 metal nanoparticle (NP) catalysts for   their antifungal activities against Candida albicans ATCC 90028.   Initial characterization using scanning electron microscopy (SEM)   suggested that our ability to detect NP binding to Candida   surfaces with this method was impeded by preparation artifacts.   As an alternative method for visualizing NP binding, we used an   enhanced dark field illumination system (CytoViva) attached to a   standard light microscope. When viewed using this system, all NP   produced intense optical signals due to resonant light   scattering. To assay binding, NP were allowed to interact with C.   albicans hyphae and cells in spent RPMI broth for 15 min with   gentle inversion, followed by viewing with the CytoViva system.   The antifungal efficacy of NP preparations was determined   separately using a 24-h broth microdilution test. For   single-metal NP, observations of binding at 15 min made via   CytoViva corresponded to antifungal efficacy at 24 h, with the   most antifungal NP yielding complete coverage of hyphal surfaces.   Our work suggests the utility of visual screening using the   CytoViva system for rapid, simple and artifact-free viewing of   NP-cell interactions in support of antimicrobial screening   efforts. This approach provides a quick and accessible   alternative to SEM for imaging of NP-cell interactions.

      Address (URL): http://www.ncbi.nlm.nih.gov/pubmed/19492326