An ELISA using an SDS extract of Brucella abortus strain 99 as antigen to detect B. abortus antibodies in cattle sera.

An ELISA was developed using an SDS extract of Brucella abortus as antigen to detect antibodies in cattle sera. The antigen was stable at 4 degrees C for at least 4 years and although it gave optimal results at a 1/4,000 dilution it could detect reactors at a 1/32,000 dilution. Based on comparative CF tests on 430 sera from negative herds and 187 sera from positive herds a reading of 0,07 or less using a 492 nm filter could be considered a negative reaction. The ELISA could be a useful test to supplement the CF test but further evaluation is still required.