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Updated: Jan 4, 2026
A Microfluidic Device for Quantifying Bacterial Chemotaxis in Stable Concentration Gradients
Published on: April 19, 2010
Development and evaluation of a sensitive, Diffusive Gradients in Thin-Films (DGT) method for determining
1Plant and Soil Sciences, N-122 Agricultural Science Building North, University of Kentucky, Lexington, KY 40546, United States.
Abstract:
A Diffusive Gradients in Thin-Films (DGT) passive sampling technique was developed for microcystin-LR (MC-LR), one of the most common and toxic microcystins. Three types of resins (HP20, SP700, and XAD18) were evaluated for MC-LR uptake kinetics, capacities, and extraction efficiencies and simple procedures were developed for determining MC-LR concentration in binding disc extracts by Adda-ELISA (U.S. EPA Method 546). The XAD18-DGT/Adda-ELISA method had a 7-d deployment time detection limit of ≈0.05 μg/L and capacity of >250 μg/L of MC-LR in water samples which encompass U.S. EPA and WHO advisory concentrations for drinking and recreational waters. The XAD18-DGT/Adda-ELISA method determined time-averaged MC-LR concentrations in waters with wide ranging pH (4.9-8.3) and ionic strength (0.04-0.8 M) under well-stirred and quiescent conditions with 90-101% accuracy. In addition to high sensitivity and accuracy, the method is simple, inexpensive, and applicable for determining MC-LR and related MCs concentrations in waterbodies with wide ranging chemical characteristics and hydrodynamic conditions.
