SCREENING OF HYBRIDOMA SECRETING MCAB TO ENROFLOXACIN AND DEVELOPMENT OF COMPETITIVE ELISA ENR-KIT DEVELOPMENT OF DIRECT COMPETITIVE ELISA KIT FOR SUDAN Ⅰ PREPARATION OF MONOCLONAL ANTIBODY AND DEVELOPMENT OF AN INDIRECT COMPETITIVE ELISA METHOD FOR GENTAMICIN Production of a Monoclonal Antibody Against Olaquindox and Development of an Indirect Competitive ELISA Method