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.

• Very small amount of sample required                 
• High reproducibility and sensitivity                 
• Very good correlation with AMES test                 
• Rapid answers in only 3 hours                  
• Low labor costs; automatic reading of kinetic data                 
• No test organism maintenance required                 
• 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: 

• A prescreening test in pharmaceutical and biotechnology laboratories to speed up the product discovery phase
• Validation of environmental compliance or in other industrial applications