We describe a protocol for colorimetric detection of E. coli using a modified litmus test that takes advantage of an RNA-cleaving DNAzyme, urease, and magnetic beads.
Tram, K., Manochehry, S., Feng, Q., Chang, D., Salena, B. J., Li, Y. Colorimetric Detection of Bacteria Using Litmus Test. J. Vis. Exp. (115), e54546, doi:10.3791/54546 (2016).