UNIT 18.2 Local Lymph Node Assays

  1. Rebecca J. Dearman,
  2. Ian Kimber

Published Online: 1 JUN 2004

DOI: 10.1002/0471140856.tx1802s20

Current Protocols in Toxicology

Current Protocols in Toxicology

How to Cite

Dearman, R. J. and Kimber, I. 2004. Local Lymph Node Assays. Current Protocols in Toxicology. 20:18.2:18.2.1–18.2.12.

Author Information

  1. Syngenta Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire, United Kingdom

Publication History

  1. Published Online: 1 JUN 2004
  2. Published Print: JUN 2004


The murine local lymph node assay (LLNA) allows identification of chemicals that have the potential to cause skin sensitization and allergic contact dermatitis. In this test, contact allergens are identified as a function of events occurring during the induction phase of skin sensitization; specifically, stimulation of proliferative responses in draining lymph nodes measured as a function of radiolabeled thymidine incorporation in situ. Two methods are presented. In one, lymph nodes are pooled on an experimental group basis, while in the other, lymph nodes of individual animal are pooled, which enables statistical analyses. These methods have been developed for contact sensitization hazard assessment and provide a robust and reliable method as an alternative to guinea pig tests which measure skin sensitizing potential as a function of challenge-induced skin reactions in previously sensitized animals. It is also possible to use LLNA data for measurement of relative potency in terms of risk assessment.


  • contact allergy;
  • local lymph node assay;
  • hazard identification;
  • potency