Methods for the characterization of microorganisms on solid or semi-solid media

A method of detecting and characterizing a microorganism on a solid or semi-solid medium, comprising:

• (a) scanning a solid or semi-solid medium, known to contain, or that may contain one or more microorganism colonies to locate any colonies present on the medium;
• (b) interrogating one or more of said colonies located during step (a) with an excitation beam that is smaller in diameter than the colony to be interrogated, to produce intrinsic fluorescence (IF) measurements characteristic of a microorganism in said colony;
• and
• (c) characterizing the microorganism in the colony based on said intrinsic fluorescence (IF) measurements, wherein said microorganism is characterized into one or more classification models selected from the group consisting of Gram Groups, Clinical Gram Groups, Therapeutic Groups, Functional Groups, and Natural Intrinsic Fluorescence Groups.