Colorimetric Detection of Bacteria Using Litmus Test.
There are increasing demands for simple but still effective methods that can be used to detect specific pathogens for point-of-care or field applications. Such methods need to be user-friendly and produce reliable results that can be easily interpreted by both specialists and non-professionals. The litmus test for pH is simple, quick, and effective as it reports the pH of a test sample via a simple color change. We have developed an approach to take advantage of the litmus test for bacterial detection. The method exploits a bacterium-specific RNA-cleaving DNAzyme to achieve two functions: recognizing a bacterium of interest and providing a mechanism to control the activity of urease. Through the use of magnetic beads immobilized with a DNAzyme-urease conjugate, the presence of bacteria in a test sample is relayed to the release of urease from beads to solution. The released urease is transferred to a test solution to hydrolyze urea into ammonia, resulting in an increase of pH that can be visualized using the classic litmus test.
Department of Biochemistry and Biomedical Sciences, McMaster University.
Kha
K
Tram
Department of Biochemistry and Biomedical Sciences, McMaster University.
Sepehr
S
Manochehry
Department of Chemistry and Chemical Biology, McMaster University.
Qian
Q
Feng
Department of Biochemistry and Biomedical Sciences, McMaster University.
Dingran
D
Chang
Department of Medicine, McMaster University.
Bruno J
BJ
Salena
Department of Biochemistry and Biomedical Sciences, McMaster University; liying@mcmaster.ca.
Yingfu
Y
Li
D000641:Ammonia / Q000032:analysis; D001419:Bacteria / Q000201:enzymology / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D021881:DNA, Catalytic / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D019095:Point-of-Care Systems; D014510:Urease / Q000737:chemistry
D021881:DNA, Catalytic; D004800:Enzymes, Immobilized; D000641:Ammonia; D014510:Urease
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