although the indirect hemagglutination technique usually showed more cross-reactivity among serogroups than the indirect fluorescent-antibody technique with formalin-fixed antigens and a conjugate which detected primarily immunoglobulin g antibodies , heterologous serogroup reactions were significantly lower than homologous serogroup titers and the etiological serogroup could be easily defined .
C0020852
immunoglobulin g
C0003241
antibodies