To enable further studies of immune responses of grass carp (Ctenopharingodon idella) especially
during the outbreaks of infectious diseases an IgM-like immunoglobulin was isolated from pooled
grass carp anti-goat IgG sera. The immunolglobulin was purified by means of gel filtration,
affinity and ion-exchange chromatography columns as two distintct peaks, but the two peaks
(IgMs) seems to be different in molecular natures. The molecular weight of the unreduced IgM
was determined to be 480-640 kilo Daltons (KD) when estimated by dodocyl sulfate-polyacrylamide
gel electrophoresis (SDS-PAGE). The amount of IgM was found to range from 3 to 4mg/
ml serum.
