To isolate avian influenza virus from suspective dead chicken caused by AIV,and detect its subtype,the SPF chicken embryo was used.After electron microscope observation of the virus from allantoi fluid,HA and HI experiments and RT-PCR were used to detect its subtype.The result showed that the AIV was confirmed as H5 subtype.RT-PCR was used to detect its HA and NA gene,its subtype was defined as H5N1.The analysis of the isolated AIV NA gene showed that this NA gene hold 97% homology with GenBank strain(EU429747),but had obvious mutation at 3′end.

The pathohistology and PCR methods were applied for the detection of PRRSV and PCV2 of sick swine tissues from a pig farm in Jilin province.The results showed there was co-infection of PRRSV and PCV2 among the sick swines.The cloning analysis of PCR amplification of PRRSV demonstrated higher identity to the base sequence of the template(EF112445.1).