Using patented optical technology, the IMD-A system is capable of simultaneously detecting both size and biologic fluorescence of airborne particulates. The technology offers an eloquent yet robust method for determining the microbial content of an aerosol sample on a particle-by-particle basis, thereby providing a continuous, real-time analysis of environmental bioburden. The IMD-A system requires no reagents and minimal human operator involvement, so it is particularly well-suited for rigorous environmental monitoring applications where time, cost, and cleanliness are of greatest concern.