Project Description
Direct Peptide Reactivity Assay (DPRA)
SERVICE INFORMATION
The OECD 442C direct peptide reactivity assay (DPRA) investigates the molecular initiating event of the AOP for skin sensitisation – haptenation. Utilising HPLC, the potential for the reactivity of a test substance to cysteine and lysine peptides is detected. Depletion of these peptides via test substance reactivity is used to support the discrimination between skin sensitisers and non-sensitisers.
Gentronix have validated their DPRA protocols to demonstrate proficiency for the OECD guideline, and now conduct these routinely to GLP.
OECD Guideline | OECD 442C |
Adverse Outcome Pathway Key Event | Number 1 – the molecular initiating event (MIE) |
What it measures | Peptide reactivity; the depletion of cysteine and lysine |
What is the relevance of that? | Covalent binding of a substance to skin proteins is considered the first step in skin allergenicity |
Incubation time | 22-24 hours |
Can be conducted to GLP? | Yes |
Protocol performed | EURL ECVAM DB-ALM Protocol No 154 |
DPRA OECD 442C Proficiency Data
GENTRONIX RESULTS | ||||
---|---|---|---|---|
Test Chemical | in vivo classification | Reactivity Class | DPRA Classification | Classification Correct? |
DNCB | Sensitiser (extreme) | High | Sensitiser | |
Oxazolone | Sensitiser (extreme) | High | Sensitiser | |
Formaldehyde | Sensitiser (strong) | Moderate | Sensitiser | |
Benzyliden acetone | Sensitiser (moderate) | High | Sensitiser | |
Farnesal | Sensitiser (weak) | Moderate | Sensitiser | |
2,3-butanedione | Sensitiser (weak) | High | Sensitiser | |
1-Butanol | Non-sensitiser | No/Minimal | Non-sensitiser | |
6-methyl coumarin | Non-sensitiser | No/Minimal | Non-sensitiser | |
Lactic acid | Non-sensitiser | No/Minimal | Non-sensitiser | |
4-methoxy acetophenone | Non-sensitiser | No/Minimal | Non-sensitiser |