A high-throughput bioluminescent
genotoxicity and cytotoxicity test
The Vitotox Test System is a
unique method for rapid and cost effective
high-throughput genotoxicity and toxicity
screening.
Patent-pending assay principle
Two recombinant Salmonella
typhimurium TA104 test strains are used in
the assay to determine simultaneously both
genotoxicity and cytotoxicity of the sample. The
test is based on luciferase reporter gene system
which activity is measured by light emission and
is a function of the genotoxicity of the test
compound. Normally, the luciferase reporter gene
is strongly repressed, but in the presence of a
DNA damaging genotoxic compound the initiation
of a cascade of reactions known as the SOS
response will take place leading to derepression
of the very strong promoter controlling the
luciferase gene.
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Very small amount of sample
required
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High reproducibility and
sensitivity
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Very good correlation with
AMES test
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Rapid answers in only 3
hours
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Low labor costs; automatic
reading of kinetic data
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No test organism maintenance
required
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96- or 384-well microplate
format
Benefits of the system
One of the major benefits over
the Ames test is that the entire DNA content of
the cell functions as a target for the genotoxin
to display its effect. In contrast, the Ames
test monitors mutations only in genes related to
histidine synthesis. This results in a
significantly lower sample concentrations (up to
1000 fold) required for the Vitotox test.
Simultaneously cytotoxicity assay
An important control for the
system is a cytotoxicity test performed together
with each sample to ensure that a positive
signal in the genotoxicity test is not due to a
nonspecific enhancement in luminescence and that
a negative response is not due to toxicity of
the test compound resulting in cell death.
Performing Vitotox assay
The test is very simple and cost
efficient to perform. Compounds are pipetted
into 96-well or 386-well microplates in a
dilution series along with blanks, positive
control samples, and with or without S9
metabolic extract. The cultured test bacteria
are added and the plate is measured repeatedly
for the three-hour assay period.
Optimal performance with
Luminoskan Ascent
Vitotox can be optimally
performed with Luminoskan Ascent. A fully
automatic measurement and data analysis system,
based on Ascent Software, runs the kinetic
Vitotox assay, then automatically
analyses the data and generates the report with
all the test results.
Special 384 well format for HTS
With the 384-well microtiter
plate setup, 23 samples can be simultaneously
tested. Combining this with the Assist robot it
is possible to easily test over 800 compounds
during one working day. This allows integrating
the Vitotox test in a high-throughput screening
program.
Small sample amount required
Since the Vitotox test is
miniaturized and very sensitive, only small
amounts of the test compound are required to
perform the test. This makes Vitotox test
usefull as a prescreening for the Ames test for
early identification of compounds that would
ultimately be eliminated by Ames testing in the
initial stage of the product discovery phase.
Application areas of the Vitotox
assay
Vitotox is ideal for laboratories
that currently use the government standard AMES
test. It can be used as:
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A prescreening test in
pharmaceutical and biotechnology
laboratories to speed up the product
discovery phase
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Validation of environmental
compliance or in other industrial
applications
