Counterimmunoelectrophoresis for Identification of Infectious Pancreatic Necrosis Virus After Isolation in Cell Culture

Abstract

An isolate of IPNV identified by seroneutralization test as serotype VR-299 was produced in RTG-2 cells, purified by density gradient centrifugation, and used to prepare the immune serum. Parameters of the CIE technique were adapted for the IPNV and one precipitin line was observed either with the purified antigen or with known positive specimens. A greater number of fish organ homogenates were positive after multiple passages in cell cultures than by direct CIE examination. However, the precipitin antigen was detected in cell culture fluid at early passages. The use of CIE following virus isolation in cell culture is recommended for routine identification of IPNV.