The ultraviolet aerodynamic particle sizer (UVAPS) system is a promising real-time method for the rapid detection of airborne microorganisms as part of public health monitoring and military defense against biological agent attacks. The UVAPS is an airborne particle counter and spectrometer capable of measuring the fluorescence emitted by living microorganisms between 0.5 and 15 µm in size. In this study, we used the UVAPS system to detect and determine the size of various test aerosols. Tests were performed using bacterial (e.g., Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis) and non-bacterial aerosols (e.g., NaCl, polystyrene latex, and fluorescent polystyrene latex particles). The aerosol and fluorescence characteristics obtained from these laboratory evaluations enabled us to distinguish between the bacterial and non-bacterial particles. In addition, the biological viability obtained from the sampled bacterial particles was compared with their fluorescence percentage. The fluorescence percentage of the tested bacterial particles was higher than that of the tested non-fluorescent particles. Although, the difference was < 8%.