Rapid in situ hybridization (ISH) technique was developed for the detection of fish microsporidian parasites. All developmental stages of Glugea plecoglossi including the initial stage immediately after entry into the fish tissue could be detected by rapid ISH using DIG-labelled oligonucleotide probes. However, ISH signals were only faintly visible from mature spores of Microsporidium seriolae, while the pre-sporogonic stages were clearly positive.Thus, it is recommended to use both rapid ISH and Uvitex 2B stain for the detection of all stages of M. seriolae. The rapid ISH allows the whole process to be completed within 2h, and thus this technique is both convenient and practical as a diagnostic and research tool for studying the life cycle of microsporidians.
The Japanese Society of Fish Pathology