A modified technique of guinea pig testing to identify delayed hypersensitivity allergens.

A modified guinea pig testing technique was developed for the detection of weak allergens and allergenicity of materials unsuitable for testing by intradermal injection. This test involved the use of Freund's complete adjuvant to stimulate the immune system of the animal, and external application instead of intradermal injection of the test compound in the induction stage. The allergenicity of Sudan III, Brilliant Lake Red R and Sudan I was tested by this procedure. In the dose-effect study of Sudan I, the dose dependency of a positive reaction of the induction and challenge concentrations was recognized. The test was compared with three other guinea pig sensitization tests. The results obtained with this test correlated well with those obtained with the guinea pig maximization test.