As part of the voluntary National Paratuberculosis Certification Program developed by the United States Animal Health Association - Johnes Committee, the National Veterinary Services Laboratories (NVSL) were asked to develop a program to approve laboratories to perform tests for the diagnosis of Johnes Disease. Guidelines have been developed for antibody-based and organism-based tests. Laboratories are evaluated on their ability to perform the ELISA, although test performance can be provided for the complement fixation (CF) and AGID tests if requested. Faecal culture is the standard for the organism-based test although DNA probe tests are also evaluated if requested. The test panels consist of sera and faecal samples from known naturally infected culture positive cattle and known culture negative cattle herds. An approved laboratory must pass an annual check test to maintain its status. If a laboratory fails to meet the established criteria, this does not prevent them from performing the tests since Johnes Disease is not an official USDA disease control or eradication program at the present time. However, the national program guidelines recommend that each state only send samples to NVSL approved laboratories. Efforts are also being made to standardise the faecal culture methods and develop quality control guidelines for laboratory procedures and media.