Abstract: A rapid and effective method is provided for determining various genotypic and/or phenotypic characteristics of an unknown microbial organism in a non-destructive manner. Initially, a predetermined growth medium is inoculated with an unknown microbial organism to create a microbial culture and the culture is then scanned at a time after inoculation to obtain a spectral signature. This scanning step is conducted utilizing wavelengths over a portion of the electromagnetic spectrum from 700-5000 nm. Thereafter, characterizing data of the unknown organism is determined from the spectral signature. This characterizing data of the unknown organism is compared with a preexisting library of characterizing data of known organisms with known characteristics, which library was made by scanning known organisms in the same manner as the unknown organism, to determine if there is a match between the characterizing data of the unknown organism and the characterizing data of a known organism contained in the library.