Toxys is a Dutch biotech company that provides innovative in vitro toxicity screening solutions to rapidly identify hazardous and potential carcinogenic properties of novel compounds during the early phases of product and drug development.


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Frequently Asked Questions

These are some of the typical questions we get asked about our technology platform. Should you not be able to find your question please feel free to contact us.

Can we send compounds to Toxys for testing?

Yes, we regularly screen test compounds for our customers in our laboratories as contracted service. We have a standard protocol for how we test compounds, but custom assay design is possible, we try to work as flexible as possible to accommodate your need.

Is it possible to use the ToxTracker assay in house?

Yes, we can provide the cells and install the assay in your laboratory under license. Please contact us via the contact form or via to find out more.

How long does it take to receive the final report?

Depending on the size of the project it takes approximately 1-2 weeks before delivery of a final report. Please contact us in case you have specific requirements, for example to fast-track a report or for large size projects.

How much compound is required?

This depends on the compound and maximum concentration you wish to test. Usually 10 mg is sufficient for the test. This can be either dry powder material or as solution.

What type of solvent can I use?

The type of solvent shall be agreed upon before start of the project. Typically DMSO or water is used, but other solvents are possible.

Can you test auto fluorescent materials?

Usually it is possible to test auto-fluorescent materials. In our standard protocols we run along a non-GFP cell line to check for auto-fluorescence. Usually we can correct for the auto-fluorescence, however occasionally the auto-fluorescence is so strong that it interferes with the flow-cytometry measurements. If this is picked-up in the dose finding study we will revert to other technologies to measure reporter induction.

Can you also test with metabolic activation?

Yes, we can add S9 liver extract to our assays for drug metabolism

What is the comparison of the ToxTracker assay with other tests?

The ToxTracker assay is highly specific and sensitive. Please see this publication for more information.

How is the ToxTracker assay validated?

Over 450 compounds have been tested in the assay. We have screened the ECVAM library and demonstrated the  sensitivity and specificity  of the ToxTracker assay. Please see our publications and ToxTracker information page.

Can you show me some typical results?

Example  report is available, please contact us via the contact form or for more information.

I would like to have additional genotoxicity testing, is that possible?

Yes, our scientist have extensive experience in genotoxicity and would like to design the optimal project for your needs. Please contact us via the contact form or to find out more about custom projects.

Why doesn't ToxTracker use human stem cells?

We often get asked why we are not using human stem cells. There are various reasons why there is no direct advantage over our current cells:

  1. nearly all compounds that give rise to genotoxicity in humans will also do this in mouse cells – the predictivity of over 95% is already excellent and is not expected to increase a lot using human cells
  2. protocols to keep stem cells untransformed are not easily available for human stem cells
  3. the major difference between human cells and mouse cells is the metabolising system, however in human stem cells this is also not present
  4. the validation with over 400 compounds has been done in the current system and would need to be redone should we redevelop the system, this requires investment in lots of time and costs
  5. should we develop a human cell system it is expected that this will be a lot more expensive given the need for expensive media etc.

Based on all these reasons we have chosen to stick with our current system and not develop a human genotoxicity assay. Of course for other applications we will consider using human cell systems.

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