DNA hybridization assay using probes prepared from liver was carried out to identify species characterization of the domestic animals. Gel electrophoresis showed that the target DNA extracted from raw muscle were 1kb and uniform pattern while fragments size of heated muscle were irrgular. Hybridizatino was performed by adding 200ng/ml probe in hybridization solution and incubating for 12 hours at 68 degrees centigrade. To obtain good discrimination, applied washing buffer and washing step differently depending on the species. The probes of pig, horse and dog formed the specific hybrids with each target DNA respectively. Although cross reaction ws detected in cattle, goat and sheep but signal intensity among these species made the discrimination possible each other. Such pattern was the same in the cases of chicken, turkey and duck. The hybridization pattern of heated muscle was similar to that of raw muscle in general, but the signal intensity was inferior to that of raw muscle. Species identification between closely related animal species, hybridized using the target DNA of such closely related animal species as a blocking agent, remarkable increase of discrimination from the evident decrease of non specific reaction compared with the control group. In addition, in the admixture where certain meat was included in the beef, pork, chicken meat, we colud find whether any unjust meat was admixed or not. In this case, detection limit of certain meat in admixture was 1%.

We have developed in situ hybridization(ISH) technique for rapid diagnosis of canine distemper(CD) which is the major infectious disease in dogs. In our experiment, we rapidly detected distribution of the specific canine distemper viral genome without disrupting morphology of tissues of cells. Two oligonucleotide probes for ISH were synthesized chemically and labelled 5' end with nonisotopic biotin by DNA synthesizer. The whole procedures of ISH was completed within 1~2 hours using the Microcapillary action system. On histological study, typical cytoplasmic or intranuclear inclusion bodies wer observed in the trachea, bronchiole, brain, and urinary bladder with the presence of prominent red positive signals on ISH, indicating specific CDV genome from the paraffin-embedded tissues of infected 13 cases. The results showed ISH can be used as a rapid and effective diagnostic method for diagnosis of CD.