title: Rainbow trout complement fixation used for titration of antibodies against several pathogens.
abstract: Since it is impossible to fix guinea pig complement (C) with Rainbow Trout (Salmo gairdneri) antibodies, whereas it is possible with Brown Trout (Salmo trutta) antibodies, a C fixation test has been designed which uses haemolysin and C from Rainbow Trout. Immunization of trout against lysed sheep red blood cells (SRBC) elicited production of haemolytic IgM. Normal trout serum (NTS) can be used as a source of C at a dilution at which its "natural" haemolytic activity (against various homeotherms RBC) has disappeared. Heating of trout C 30 min at 37 degrees C leads to a 75% loss of its activity, and this one is completely abolished at 40 degrees C. Fixation of 3 to 4 CH50 units has been achieved in a short test (2 h at 20 degrees C) for the following antigen-antibody systems: 2 bacterial antigens (Aeromonas salmonicida and Vibrio anguillarum); 2 viruses (Infectious Pancreatic Necrosis (IPN) virus and Egtved Virus). C fixation has a sensitivity comparable with agglutination in the case of A. salmonicida. For IPN Virus, sero-neutralization is 50 times more sensitive than C fixation. In the case of Egtved virus, the difference is not so great.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D000917:Antibody Formation; D003168:Complement Fixation Tests; D005399:Fishes / Q000276:immunology*; D006460:Hemolysin Proteins / Q000032:analysis
chemical_list: D000907:Antibodies, Bacterial; D006460:Hemolysin Proteins