Method and apparatus for detecting the presence of microbes and determining their physiological status

Abstract

Method and apparatus for the detection of microbes in liquids, in air and on non-living surfaces in which samples are exposed to electromagnetic radiation of specific energies capable of exciting various metabolites, cofactors and cellular and spore components, with the microbial cells to be sampled (and more specifically the excited metabolites, cofactors and/or other cellular components) contained therein emit fluorescence that can be measured. The signal from the background and scattered excitation signals is removed from the fluorescence signals of the microbial components, the relative fluorescent signals of the intrinsic microbial components are required to lie within physiological ranges, and the amplitude of the background-corrected fluorescence signals used to enumerate the microbe content in the sample.

What is claimed:  
     
         14 . Apparatus for the detection of microbes on a non-living surface or in air or liquid comprising: 
 a. means for directing electromagnetic radiation towards the sample, said means adapted to emit radiation energies capable of exciting at least one intrinsic microbial fluorophore;    b. at least one detector for electromagnetic radiation capable of converting the emitted, or reflected/scattered radiation into electrical signals, said detector adapted to detect electromagnetic radiation at wavelengths above 320 nm to detect the minima and maxima associated with the fluorescence emission of said microbial fluorophores; and    c. means for analyzing the electrical signals corresponding to the fluorescence of the intrinsic microbial fluorophores, and the reflected/scattered excitation energies to determine the presence of microbes.    
     
     
         15 . The method as defined in claim  1  wherein the electromagnetic waves are directed towards the microbes in time-modulated pulses.  
     
     
         16 . The apparatus defined in  claim 14  wherein the means for directing electromagnetic radiation includes means for time-modulating the electromagnetic radiation.