TY - JOUR
T1 - A flow cytometry-optimized assay using an SOS-green fluorescent protein (SOS-GFP) whole-cell biosensor for the detection of genotoxins in complex environments
AU - Norman, Anders
AU - Hansen, Lars H.
AU - Sørensen, Søren Johannes
N1 - Keywords: SOS-response; Green fluorescent protein (GFP); Whole-cell biosensor; Flow cytometry; Genotoxicity; Mitomycin C; Soil microcosms
PY - 2006
Y1 - 2006
N2 - Whole-cell biosensors have become popular tools for detection of ecotoxic compounds in environmental samples. We have developed an assay optimized for flow cytometry with detection of genotoxic compounds in mind. The assay features extended pre-incubation and a cell density of only 106-107 cells/mL, and proved far more sensitive than a previously published assay using the same biosensor strain. By applying the SOS-green fluorescent protein (GFP) whole-cell biosensor directly to soil microcosms we were also able to evaluate both the applicability and sensitivity of a biosensor based on SOS-induction in whole soil samples. Soil microcosms were spiked with a dilution-series of crude broth extract from the mitomycin C-producing streptomycete Streptomyces caespitosus. Biosensors extracted from these microcosms after 1 day of incubation at 30 °C were easily distinguished from extracts of non-contaminated soil particles when using flow cytometry, and induction of the biosensor by mitomycin C was detectable at concentrations as low as 2.5 ng/g of soil.
AB - Whole-cell biosensors have become popular tools for detection of ecotoxic compounds in environmental samples. We have developed an assay optimized for flow cytometry with detection of genotoxic compounds in mind. The assay features extended pre-incubation and a cell density of only 106-107 cells/mL, and proved far more sensitive than a previously published assay using the same biosensor strain. By applying the SOS-green fluorescent protein (GFP) whole-cell biosensor directly to soil microcosms we were also able to evaluate both the applicability and sensitivity of a biosensor based on SOS-induction in whole soil samples. Soil microcosms were spiked with a dilution-series of crude broth extract from the mitomycin C-producing streptomycete Streptomyces caespitosus. Biosensors extracted from these microcosms after 1 day of incubation at 30 °C were easily distinguished from extracts of non-contaminated soil particles when using flow cytometry, and induction of the biosensor by mitomycin C was detectable at concentrations as low as 2.5 ng/g of soil.
U2 - 10.1016/j.mrgentox.2005.11.008
DO - 10.1016/j.mrgentox.2005.11.008
M3 - Journal article
VL - 603
SP - 164
EP - 172
JO - Mutation Research - Reviews
JF - Mutation Research - Reviews
SN - 1383-5742
IS - 2
ER -