Development of a sensitive chemiluminometric assay for the detection of beta-galactosidase in permeabilized coliform bacteria and comparison with fluorometry and colorimetry.
We developed a chemiluminometric assay of beta-galactosidase in coliform bacteria, using a phenylgalactose-substituted 1,2-dioxetane derivative as a substrate. Permeabilization of cells is required to ensure the efficient cellular uptake of this compound. By this method, one coliform seeded in 100 ml of sterile water can be detected after a 6- to 9-h propagation phase followed by a 45-min enzyme assay in the presence of polymyxin B. Compared with fluorometry and colorimetry, chemiluminometry afforded 4- and 1,000-fold increases in sensitivity and 1- and 6-h increases in the speed of detection, respectively.
Van Poucke
S O
SO
Department of Pharmaceutical Analysis, University of Ghent, Belgium.
Nelis
H J
HJ
D003124:Colorimetry; D004755:Enterobacteriaceae / Q000201:enzymology* / Q000302:isolation & purification; D005470:Fluorometry; D008163:Luminescent Measurements; D012680:Sensitivity and Specificity; D014871:Water Microbiology; D001616:beta-Galactosidase / Q000032:analysis*
D001616:beta-Galactosidase