The IDEXX Leukosis Serum Screening Ab Test detects all types of antibodies against the virus (e.g., envelope proteins, capsid proteins) in individual or pool sera. The test are based on the use of an ultrapurified virus lysate and are standardized to detect the European standard serum for (E5) diluted to 1:100 in negative bovine serum, according to the requirements of the Council Directive 64/432/EEC (modified on December 11, 1984, June 26, 1991 and March 2001).