OECD Guidelines for the Testing of Chemicals, Section 4
- 2074-5788 (online)
The OECD Guidelines for the Testing of Chemicals is a collection of about 150 of the most relevant internationally agreed testing methods used by government, industry and independent laboratories to identify and characterise potential hazards of chemicals. They are a set of tools for professionals, used primarily in regulatory safety testing and subsequent chemical and chemical product notification, chemical registration and in chemical evaluation. They can also be used for the selection and ranking of candidate chemicals during the development of new chemicals and products and in toxicology research. This group of tests covers health effects.
Test No. 442A: Skin Sensitization
Local Lymph Node Assay: DA
- 23 July 2010
- 9789264090972 (PDF)
The Local Lymph Node Assay: DA (LLNA: DA) is a non-radioactive modification to the LLNA method for identifying potential skin sensitizing test substances and measuring the proliferation of lymphocytes they induce in the auricular lymph nodes. The method, described in mouse (CBA/J strain), is based on measurement of the adenosine triphosphate (ATP) content by bioluminescence as an indicator of this proliferation. A minimum of four animals is used per dose group, with a minimum of three concentrations of the test substance, plus a concurrent negative control group and, if appropriate, a positive control group. The experimental schedule is during 8 days. The time from animal sacrifice to measurement of ATP should not exceed 30 min. The procedure from excision of lymph nodes to ATP measurement should be kept uniform for each animal and completed within 20 minutes. The luciferin/luciferase method is applied to measure the bioluminescence in Relative Luminescence Units (RLU). This study includes: measurements (weighing, RLU), and clinical daily observations. The results are expressed as the Stimulation Index (SI) obtained by calculation. The SI should be ¡Ý1.8 before further evaluation of the test material as a potential skin sensitizer is warranted.