Identification and Elimination of Sources of Extraneous Background Signal in Laser-Induced Breakdown Spectroscopy Spectra of Bacterial Cells Deposited on Filtration Media
Standing
Undergraduate
Type of Proposal
Visual Presentation (Poster, Installation, Demonstration)
Faculty
Faculty of Science
Faculty Sponsor
Steven J. Rehse
Proposal
Our lab has been investigating the use of laser-induced breakdown spectroscopy (LIBS) for the rapid identification of bacteria in clinical specimens. The ability to rapidly identify harmful pathogens in such specimens is crucial for initiating appropriate treatment of infectious diseases that can kill within hours of the onset of symptoms. Current laboratory techniques can take as long as 24-72 hours for a positive identification. Our research program is attempting to reduce that time to minutes. The current protocol involves concentrating the bacterial cells in a liquid suspension into a small circular deposition area 1 mm in diameter upon a nitrocellulose filter medium (with pore size of 0.45 microns) by centrifuging the suspension through a custom-fabricated cone device. A pulse of high-intensity laser light focused onto the circular deposition allows a sensitive measurement of the elemental composition of the cells, leading to the detection and identification of the bacteria. By reducing the cell concentration in various suspensions, the limit of detection may be calculated. Laser ablation of the filter medium and other elemental contaminants yields a non-zero background signal when a control experiment is performed in the absence of bacterial cells. In this poster we will present our work to identify exactly what the sources of this non-bacterial signal are, and to add preparation steps to the protocol which might reduce or eliminate this undesired background signal. In addition, the investigation of other types of filter media which may contribute a reduced background signal will be discussed.
Location
University of Windsor
Grand Challenges
Viable, Healthy and Safe Communities
Special Considerations
This is a single poster being presented by four students: one of whom is a graduate student (Marvin) the other three are undergraduates. The students present during the designated time will depend on labs and exams scheduled that week.
Identification and Elimination of Sources of Extraneous Background Signal in Laser-Induced Breakdown Spectroscopy Spectra of Bacterial Cells Deposited on Filtration Media
University of Windsor
Our lab has been investigating the use of laser-induced breakdown spectroscopy (LIBS) for the rapid identification of bacteria in clinical specimens. The ability to rapidly identify harmful pathogens in such specimens is crucial for initiating appropriate treatment of infectious diseases that can kill within hours of the onset of symptoms. Current laboratory techniques can take as long as 24-72 hours for a positive identification. Our research program is attempting to reduce that time to minutes. The current protocol involves concentrating the bacterial cells in a liquid suspension into a small circular deposition area 1 mm in diameter upon a nitrocellulose filter medium (with pore size of 0.45 microns) by centrifuging the suspension through a custom-fabricated cone device. A pulse of high-intensity laser light focused onto the circular deposition allows a sensitive measurement of the elemental composition of the cells, leading to the detection and identification of the bacteria. By reducing the cell concentration in various suspensions, the limit of detection may be calculated. Laser ablation of the filter medium and other elemental contaminants yields a non-zero background signal when a control experiment is performed in the absence of bacterial cells. In this poster we will present our work to identify exactly what the sources of this non-bacterial signal are, and to add preparation steps to the protocol which might reduce or eliminate this undesired background signal. In addition, the investigation of other types of filter media which may contribute a reduced background signal will be discussed.