A method and apparatus for determining a presence of a microorganism in a sample is provided. The method includes storing electrophysiological and/or impedance signatures of a plurality of microorganisms in a memory of a processor. The method also includes obtaining a sample and generating an electrophysiological and/or impedance signature of the sample. The electrophysiological and/or impedance signature of the sample is compared with the electrophysiological and/or impedance signatures in the memory. A presence of one of the plurality of microorganisms in the sample is then identified based on a correlation between the electrophysiological and/or impedance signature of the sample and the electrophysiological and/or impedance signature of the one of the plurality of microorganisms. A method is also provided for determining a growth stage of a microorganism in a sample.