title: Application of quartz tuning forks for detection of endotoxins and Gram-negative bacterial cells by monitoring of Limulus Amebocyte Lysate coagulation.
abstract: Endotoxins, pyrogens of bacterial origin, are a significant threat in many areas of life. Currently, the test most commonly used for endotoxin level determination is LAL (Limulus Amebocyte Lysate) assay. This paper presents application of commercially available low-frequency piezoelectric tuning forks (QTFs) for endotoxin detection. Measurement of the decrease in the QTF oscillation amplitude provides information about the viscosity changes, occurring in the tested sample upon addition of LAL. That method was used to determine the concentrations of endotoxins and bacterial cells (E. coli O157:H19). The relevance of the obtained results was confirmed using a commercially available colorimetric LAL assay. The constructed system can detect bacterial endotoxins in the range of 0.001-5EU/ml and bacterial cells in the range of 10(2)-10(7)CFU/ml. The presented technique requires very simple sample preparation and the sensor response is obtained using compact, portable readout electronics. The single test cost is low compared to commercial endotoxin assays and other novel systems based on micromechanical sensors.
authors.affiliation: Laboratory of Medical Microbiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, 53-114 Wrocław, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Chałupniak
authors.affiliation: Faculty of Microsystem Electronics and Photonics, Wrocław University of Technology, Z. Janiszewskiego 11/17, 50-372 Wrocław, Poland.
authors.forename: Karol
authors.initials: K
authors.lastname: Waszczuk
authors.affiliation: Laboratory of Medical Microbiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, 53-114 Wrocław, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Hałubek-Głuchowska
authors.affiliation: Faculty of Microsystem Electronics and Photonics, Wrocław University of Technology, Z. Janiszewskiego 11/17, 50-372 Wrocław, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Piasecki
authors.affiliation: Faculty of Microsystem Electronics and Photonics, Wrocław University of Technology, Z. Janiszewskiego 11/17, 50-372 Wrocław, Poland.
authors.forename: Teodor
authors.initials: T
authors.lastname: Gotszalk
authors.affiliation: Laboratory of Medical Microbiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, 53-114 Wrocław, Poland. Electronic address: rybka@iitd.pan.wroc.pl.
authors.forename: Jacek
authors.initials: J
authors.lastname: Rybka
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019453:Escherichia coli O157 / Q000737:chemistry / Q000302:isolation & purification*; D006737:Horseshoe Crabs / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000032:analysis* / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D014783:Viscosity
chemical_list: D008070:Lipopolysaccharides; D008565:Membrane Proteins; C025357:endotoxin binding proteins
keywords: Endotoxin; LAL; Limulus Amebocyte Lysate; QTF; Quartz tuning fork; Viscosity measurement