The murine local lymph node assay (LLNA) is an in vivo test for skin sensitisation.
The OECD Guidelines for the Testing of Chemicals guideline No. 429 of 23 July 2010.
LLNA test has largely superseded the guinea pig maximisation test and the Buehler test.
The REACH Regulation, Annex VII, paragraph 8.3 states "The Murine Local Lymph Node Assay (LLNA) is the first-choice method for in vivo testing. Only in exceptional circumstances should another test be used. Justification for the use of another test shall be provided."
References
Local lymph node assay Wikipedia(Text) CC BY-SA