Testing fish vaccines with an in vitro lymphocyte blastogenesis assay.

Lethal-challenge experiments are provided by German law till now for testing fish vaccines. Finding an in vitro-assay which could replace this experiments was subject of our work. Two questions must have been answered to develop the lymphocyte blastogenesis assay: Do lymphocytes of immunised fish react the same way as lymphocytes of naive fish, being incubated with antigen and is there a coherence between the lymphocyte's in-vitro-response and the immune status of challenged fish.