THE IDENTIFICATION OF PATHOGENS BY LASER-EXCITED FLUORIMETRY (HYDROLASES, FLUORESCENCE)
Abstract
Laser-excited fluorimetry has been applied to the development of a rapid of pathogen identification. The aminopeptidase profiling method was used to accomplish the identification. The sensitivity and selectivity of the technique was improve by using the unique characteristics provided by laser excitation. The improvements included improving the linear dynamic range of the aminopeptidase technique by a reduction in the lower limit of detection of the tag, -naphthylamine. A bacterial identification method allowing a more rapid turn-around time was also developed. The luminescence blank was systematically examined and reduced by chemical and instrumental means to a level which allowed a 1000-fold reduction in the number of bacteria required for an identification. An identification using fewer bacteria should reduce the turnaround time for bacterial identification, since the majority of the time due to the 48 hr cell growth period. Closely-related races of one bacterial species were differentiated with 92% accuracy using the k-nearest neighbor approach to pattern recognition. A drastic improvement in recognition of races of Agrobacterium tumefaciens was achieved by eliminating many substrates from the identification compared to using all substrates hydrolyzed, since many substrates added no information toward the identification.
Degree
Ph.D.
Subject Area
Analytical chemistry|Microbiology
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