Immunoassay test for brucellosis 2-Mercapto-ethanol Test for cattle brucellosis 2-ME 2ME PubMed: 9684294 The 2ME test is usually used in serial testing to distinguish between vaccinated and infected cattle. YL a immunoassay test for brucellosis that uses 2-Mercapto-ethanol differentiates between IgM and IgG antibodies and used to identify a recent immune response to an infectious agent. (http://medical-dictionary.thefreedictionary.com/2-mercaptoethanol+(2+ME)+test)