Production of an ovine monoclonal antibody to testosterone by an interspecies fusion

Hybridomas were made between NS1/1-Ag4-1 mouse myeloma cells and peripheral blood lymphocytes from a sheep immunized with a testosterone-protein conjugate. ELISAs were developed to detect ovine IgG and specific ovine anti-testosterone and these were used to screen the colonies. Although the cells fused acceptably only 3% of colonies secreted detectable quantities of antibody. The antibody was secreted at low levels (2.5 ng/ml) but was of high affinity (KD = 7.63 x 10(-12) M/1). One line, O/M 4.22, continued to secrete in culture for four months until the termination of the experiment.