Difficult-to-test samples.

The challenges

In the context of skin sensitization testing, certain groups of chemicals are considered “difficult-to-test” using conventional cell-based methods. Examples of commonly recognised “difficult-to-test” samples include:

  • Pre- and pro- haptens

    Pre- and pro-haptens need to be activated to become skin sensitizers. The metabolic activation process, however, is not always supported by in vitro tests.

  • Low water-soluble substances

    Hydrophobic test items are often difficult to test in an aqueous test system due to solubility issues.

  • Surfactants

    Many surfactants have cell membrane-damaging properties and tend to generate false-positive results.

  • Complex mixtures

    Botanical extracts, essential oils or UVCBs are typical examples of complex mixtures. Many of them have solubility issues in aqueous test systems.

Our solution

GARDskin demonstrated over 80% predictive accuracy* for various types of difficult-to-test samples when compared to existing human data.

Supporting metabolic activation

GARDskin utilizes a dendritic-like cell line, expressing several metabolizing enzymes required for activation of pre/-pro haptens (e.g. ALDH, CYP, NAT-1).

A broad selection of solvents

The solubility for hydrophobic substances is further increased using an extended panel of non-polar solvents compatible with the test system.

Highly sensitive

GARDskin is highly sensitive, able to detect a minimum amount of substances dissolved in the cell medium.


“Applicability of GARDskin for accurate assessment of challenging substances in the context of skin sensitization testing”

*Poster abstract accepted at SOT 2020