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Description
The Kentucky Watershed Watch program, a non-profit that relies on the help of volunteers, trains Kentucky residents on proper analytical procedures needed to assess waterways near their homes. Volunteers can deliver samples to established labs for bacterial analysis or independently test sample sites’ pH, dissolved oxygen, conductivity, temperature, and Escherichia coli levels. One of the ways the Watershed Watch program analyzes water quality is by using R-Cards, sample cards that contain a chromogenic medium useful for detecting and enumerating E. coli. These cards cost $1 each and are quite simple to set up, whereby one mL of sample site water is placed beneath the plastic flap, which, when released, quickly spreads the water out across the card. The purpose of this study was to compare the accuracy/effectiveness of R-cards to the accuracy/effectiveness of the USEPA- and KDOW approved IDEXX Quanti-Trays. IDEXX trays are bacterial detection trays that utilize two enzymes, β-Galactosidase and β-D-Glucuronidase, to detect coliform bacteria and E. coli, respectively. While these trays are the standard method for E. coli enumeration/detection in water samples, each tray costs $20. Using five sets of data from a mix of 16 sample sites, colony counts were analyzed, and averages between the two enumeration methods were calculated, revealing significant disparities. By performing this study, the Watershed Watch program and other organizations that use the R-Cards will be able to decide if they should continue using them despite their drastically different results.
Publication Date
4-16-2025
Disciplines
Higher Education | Scholarship of Teaching and Learning
Recommended Citation
Mays, Heavenly; Morgan, Emily; and Gearner, Geoffrey W., "Comparative Analysis of R-Cards and IDEXX Quanti-Tray/2000 for the Detection and Enumeration of Bacteria in Environmental Water Samples" (2025). 2025 Celebration of Student Scholarship - Poster Presentations. 58.
https://scholarworks.moreheadstate.edu/celebration_posters_2025/58