Use of dried smooth lipopolysaccharide antigen coated polystyrene plates for diagnosis of bovine brucellosis by enzyme immunoassay.

Polystyrene plates (96 well) were sensitized with Brucella abortus smooth lipopolysaccharide (SLPS) antigen and then air dried at room temperature (RT) for about 1 hour to dry. Dryness was judged complete when a buffer meniscus was absent from the bottom of the well. The plates were resealed kept on the bench at RT for the duration of the study. Testing was done over 13 months by competitive and indirect ELISAs (C- and IELISA) for bovine antibody to B. abortus using panels of sera from B. abortus S19 vaccinated, unexposed and infected cattle. Testing revealed that consistent results were obtained over the test period suggesting that air drying may be a suitable alterative for storage of plates sensitized with some antigens, in particular, smooth lipopolysaccharide.