Evaluation and validation of Biolog OmniLog ^® system for antibacterial activity assays

Minimal inhibitory concentration of antimicrobials, determined by the broth microdilution method, requires visual assessment or absorbance measurement using a spectrophotometer. Both procedures are usually performed manually, requiring presence an operator to assess plates at specific time point. To increase throughput antimicrobial susceptibility testing, and concurrently convert into automatic assay, Biolog OmniLog® system was validated for new, label-free application standard 96-well microplates. OmniLog evaluated its signal strength ensure that intensity, detected measured system's camera, satisfactory. Variability due plate location inside incubator, as well variation between wells, investigated. Then determining minimal ciprofloxacin, piperacillin linezolid against selected Gram-negative Gram-positive strains. No significant difference observed in relation position within system. Plate edge effects were noticeable, thus wells not included further experiments. results comparable those obtained conventional protocol values defined Clinical Laboratory Standards Institute published literature.