The gene fragments HNa, HNb and HNa-L-b coding for the antigenic structural domains of the newcastle disease virus (NDV) hemagglutinin-neuraminidase were amplified from the recombinant plasmid containing full length NDV HN gene by regular PCR or overlap extension PCR with specific primers.

Cloning and expressing in the baculovirus expression system of NA gene of A/Swine/Inner Mongolia/547/01 isolate;

Molecular cloning and homology analysis of the NA gene of equine influenza virus(A/Equine/Qinghai/1/94)in China;