WHY CONDUCT A GARD^®skin SKIN SENSITISATION TEST?

GARD^®skin is a human genomic screen which measures changes in the expression of 200 genes relevant to the skin sensitisation AOP and is used as an alternative to the h-CLAT method for Key Event 3. It is the first in vitro skin sensitisation test to be validated for the prediction of potency. This non-regulatory test can be used as part of a weight-of-evidence approach and can be a useful alternative if your test chemical is not compatible with the KeratinoSens™ or h-CLAT tests.

XCellR8 is a distributor for the standard GARD^®skin test and exclusive global distributor for GARDskin animal product free. The animal-product-free adaptation supports ‘vegan tested’ claims and higher ethical values in your supply chain.

OVERVIEW

Skin sensitisation is defined as an allergic response following skin contact with the tested chemical, as defined by the United Nations Globally Harmonized System for Classification and Labelling of Chemicals (UN GHS).

GARD^®skin (Genomic Allergen Rapid Detection) is a non-regulatory test supporting discrimination of skin Sensitisers and Non-Sensitisers in accordance with the UN GHS. GARD™skin also provides a useful screen for product development. GARD®skin Animal-Product-Free is an adaptation of the GARD^®skin method, and the data generated should be considered in the context of an integrated approach to testing. Foetal bovine calf serum (FBS) and animal derived antibodies have been replaced with human-derived serum and antibodies produced by phage display.

The adverse outcome pathway (AOP) leading to skin sensitisation involves several key events. This test addresses Key Event 3 (activation of dendritic cells), but also provides information on genes related to processes across the entire AOP.

The GARD®skin method is an in vitro test based on a human dendritic-like cell line (SenzaCell™), a set of 200 genes known as the GARD Prediction Signature and a prediction model developed with machine learning technology.

After exposure to the test item, total RNA is isolated from SenzaCells™, gene expression is then quantified and analysed by pattern recognition technology using a machine learning algorithm based on a fixed set of reference samples. The genes measured are well characterised and are related to several skin sensitisation mechanistic events. The resulting classification is that of a sensitiser or non-sensitiser.

 Photos on this webpage by courtesy of SenzaGen ©

TEST SYSTEM: SENZACELLS™

The test system comprises of SenzaCells™ (a proprietary human dendritic-like cell line) stimulated by a test item. The SenzaCell™ RNA is isolated, the gene expression is measured and the resulting data is analyzed using a machine learning algorithm.

SUMMARY OF THE TEST METHOD

• An initial dose-response experiment (GARD Input Finder) is performed to determine a
  concentration of test item where 90% of SenzaCells™ are viable
• In the main experiment, SenzaCells™ are dosed with the concentration determined by the
  GARD Input Finder for 24-hours
• After 24-hour stimulation, the total RNA of the SenzaCells™ is extracted and isolated
• Using the isolated RNA, the changes in expression of 200 genes are measured using a
  NanoString
• The results of gene expression profiling are analysed through a prediction
  model that correlates gene expression to sensitising potential
• The results classify the test substance as a sensitiser or non-sensitiser

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