The Israeli Journal of Aquaculture - Bamidgeh 51(1), 1999, 3-9
ONE-STEP PROCEDURE FOR THE PURIFICATION
OF GOLDFISH (CARRASIUS AURATUS)
AND CARP (CYPRINUS CARPIO, L.) SERUM
IMMUNOGLOBULIN BY PRECIPITATION WITH 9%
POLYETHYLENE GLYCOL 6000
Ming-Chao Zhong, Anat Mor and Ramy R. Avtalion
Laboratory of Fish Immunology and Genetics, Faculty of Life Sciences, Bar I!an University,
Ramat Gan 52900, Israel
(Received 16.8.98, Accepted 30.11.98)
Goldfish and carp lgM was precipitated from their sera in the presence of 9% polyethylene glycol 6000. The precipitate, when solubilized in a quantity of phosphate buffer equal to the initial volume of the serum, showed an ELISA antibody activity almost equivalent to that of the initial serum. This solution gave a single lgM electrophoretic band in 3.5% SDS-PAGE under non-reducing conditions. However, neither residual ELISA antibody activity nor the presence of lgM electrophoretic bands could be detected in the supernatant after removal of the precipitate by centrifugation.
SDS-PAGE of lgMs from the above species, performed under reducing conditions, revealed appropriate heavy and light chains of 71 and 24-26 kDa that reflect a tetrameric MW of 760-768 kDa in both species. The purity of the polyethylene glycol (PEG) precipitated lgM fraction as evaluated by computerized density analysis was estimated at about 95%.